Instrument systems and methods utilizing optical fiber sensor

ABSTRACT

An instrument system that includes an elongate instrument body and an optical fiber sensor is provided. The optical fiber sensor includes an elongate optical fiber that is coupled to the elongate instrument body, wherein a portion of the optical fiber is coupled to the elongate instrument body in a manner to provide slack in the fiber to allow for axial extension of the elongate instrument body relative to the optical fiber.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional of U.S. patent application Ser.No. 12/192,033 filed on Aug. 14, 2008, which claims the benefit under 35U.S.C. §119 to U.S. Provisional Application No. 60/964,773, filed onAug. 14, 2007, the contents of which is incorporated herein by referenceas though set forth in full.

The present application may also be related to subject matter disclosedin the following applications, the contents of which are alsoincorporated herein by reference as though set forth in full: U.S.patent application Ser. No. 10/923,660, entitled “System and Method for3-D Imaging”, filed Aug. 20, 2004; U.S. patent application Ser. No.10/949,032, entitled “Balloon Visualization for Transversing a TissueWall”, filed Sep. 24, 2005; U.S. patent application Ser. No. 11/073,363,entitled “Robotic Catheter System”, filed Mar. 4, 2005; U.S. patentapplication Ser. No. 11/173,812, entitled “Support Assembly for RoboticCatheter Assembly”, filed Jul. 1, 2005; U.S. patent application Ser. No.11/176,954, entitled “Instrument Driver for Robotic Catheter System”,filed Jul. 6, 2005; U.S. patent application Ser. No. 11/179,007,entitled “Methods Using A Robotic Catheter System”, filed Jul. 6, 2005;U.S. patent application Ser. No. 11/185,432, entitled “System and methodfor denaturing and fixing collagenous tissue”, filed Jul. 19, 2005; U.S.patent application Ser. No. 11/202,925, entitled “Robotically ControlledIntravascular Tissue Injection System”, filed Aug. 12, 2005; U.S. patentapplication Ser. No. 11/331,576, entitled “Robotic Catheter System”,filed Jan. 13, 2006; U.S. patent application Ser. No. 11/418,398,entitled “Robotic Catheter System”, filed May 3, 2006; U.S. patentapplication Ser. No. 11/481,433, entitled “Robotic Catheter System andMethods”, filed Jul. 3, 2006; U.S. patent application Ser. No.11/637,951, entitled “Robotic Catheter System and Methods”, filed Dec.11, 2006; U.S. patent application Ser. No. 11/640,099, entitled “RoboticCatheter System and Methods”, filed Dec. 14, 2006; U.S. patentapplication Ser. No. 11/678,001, entitled Apparatus for Measuring DistalForces on a Working Instrument, filed Feb. 22, 2007; U.S. patentapplication Ser. No. 11/678,016, entitled Method of Sensing Forces on aWorking Instrument, filed Feb. 22, 2007; U.S. patent application Ser.No. 11/690,116, entitled Fiber Optic Instrument Sensing System, filedMar. 22, 2007; U.S. patent application Ser. No. 12/032,622, entitledInstrument Driver Having Independently Rotatable Carriages, filed Feb.15, 2008; U.S. patent application Ser. No. 12/032,634, entitled SupportStructure for Robotic Medical Instrument filed Feb. 15, 2008; U.S.patent application Ser. No. 12/032,626, entitled Instrument Assembly forRobotic Instrument System, filed Feb. 15, 2008; U.S. patent applicationSer. No. 12/032,639, entitled Flexible Catheter Instruments and Methods,filed Feb. 15, 2008; U.S. application Ser. No. 12/106,254, entitledOptical Fiber Shape Sensing Systems, filed on Apr. 18, 2008; and U.S.application Ser. No. 12/114,720, entitled Apparatus, Systems and Methodsfor Forming a Working Platform of a Robotic Instrument System byManipulation of Components Having Controllable Rigidity,” filed on May2, 2008.

The present application may also be related to subject matter disclosedin the following provisional applications, the contents of which arealso incorporated herein by reference as though set forth in full: U.S.Provisional Patent Application No. 60/550,961, entitled “RoboticCatheter System,” filed Mar. 5, 2004; U.S. Provisional PatentApplication No. 60/750,590, entitled “Robotic Catheter System andMethods”, filed Dec. 14, 2005; U.S. Provisional Patent Application No.60/756,136, entitled “Robotic Catheter System and Methods”, filed Jan.3, 2006; U.S. Provisional Patent Application No. 60/776,065, entitled“Force Sensing for Medical Instruments”, filed Feb. 22, 2006; U.S.Provisional Patent Application No. 60/785,001, entitled “FiberopticBragg Grating Medical Instrument”, filed Mar. 22, 2006; U.S. ProvisionalPatent Application No. 60/788,176, entitled “Fiberoptic Bragg GratingMedical Instrument”, filed Mar. 31, 2006; U.S. Provisional PatentApplication No. 60/801,355, entitled “Sheath and Guide CatheterApparatuses For A Robotic Catheter System With Force Sensing”, filed May17, 2006; U.S. Provisional Patent Application No. 60/801,546, entitled“Robotic Catheter System and Methods”, filed May 17, 2006; U.S.Provisional Patent Application No. 60/801,945, entitled “RoboticCatheter System and Methods”, filed May 18, 2006; U.S. ProvisionalPatent Application No. 60/833,624, entitled “Robotic Catheter System andMethods”, filed Jul. 26, 2006; U.S. Provisional Patent Application No.60/835,592, entitled “Robotic Catheter System and Methods”, filed Aug.3, 2006; U.S. Provisional Patent Application No. 60/838,075, entitled“Robotic Catheter System and Methods”, filed Aug. 15, 2006; U.S.Provisional Patent Application No. 60/840,331, entitled “RoboticCatheter System and Methods”, filed Aug. 24, 2006; U.S. ProvisionalPatent Application No. 60/843,274, entitled “Robotic Catheter System andMethods”, filed Sep. 8, 2006; U.S. Provisional Patent Application No.60/873,901, entitled “Robotic Catheter System and Methods”, filed Dec.8, 2006; U.S. Provisional Patent Application No. 60/879,911, entitled“Robotic Catheter System and Methods”, filed Jan. 10, 2007; U.S.Provisional Patent Application No. 60/899,048, entitled “RoboticCatheter System”, filed Feb. 8, 2007; U.S. Provisional PatentApplication No. 60/900,584, entitled “Robotic Catheter System andMethods”, filed Feb. 8, 2007; U.S. Provisional Patent Application No.60/902,144, entitled, Flexible Catheter Instruments and Methods, filedon Feb. 15, 2007; U.S. Provisional Patent Application No. 60/925,449,entitled Optical Fiber Shape Sensing Systems, filed Apr. 20, 2007; andU.S. Provisional Patent Application No. 60/925,472, entitled Systems andMethods for Processing Shape Sensing Data, filed Apr. 20, 2007.

FIELD OF INVENTION

The invention relates generally to robotically controlled systems suchas telerobotic surgical systems.

BACKGROUND

Robotic interventional systems and devices are well suited for use inperforming minimally invasive medical procedures as opposed toconventional procedures that involve opening the patient's body topermit the surgeon's hands to access internal organs. Traditionally,surgery utilizing conventional procedures meant significant pain, longrecovery times, lengthy work absences, and visible scarring. However,advances in technology have led to significant changes in the field ofmedical surgery such that less invasive surgical procedures areincreasingly popular, in particular, minimally invasive surgery (MIS). A“minimally invasive medical procedure” is generally considered aprocedure that is performed by entering the body through the skin, abody cavity, or an anatomical opening utilizing small incisions ratherthan larger, more invasive open incisions in the body.

Various medical procedures are considered to be minimally invasiveincluding, for example, mitral and tricuspid valve procedures, patentformen ovale, atrial septal defect surgery, colon and rectal surgery,laparoscopic appendectomy, laparoscopic esophagectomy, laparoscopichysterectomies, carotid angioplasty, vertebroplasty, endoscopic sinussurgery, thoracic surgery, donor nephrectomy, hypodermic injection,air-pressure injection, subdermal implants, endoscopy, percutaneoussurgery, laparoscopic surgery, arthroscopic surgery, cryosurgery,microsurgery, biopsies, videoscope procedures, keyhole surgery,endovascular surgery, coronary catheterization, permanent spinal andbrain electrodes, stereotactic surgery, and radioactivity-based medicalimaging methods. With MIS, it is possible to achieve less operativetrauma for the patient, reduced hospitalization time, less pain andscarring, reduced incidence of complications related to surgical trauma,lower costs, and a speedier recovery.

Special medical equipment may be used to perform MIS procedures.Typically, a surgeon inserts small tubes or ports into a patient anduses endoscopes or laparoscopes having a fiber optic camera, lightsource, or miniaturized surgical instruments. Without a traditionallarge and invasive incision, the surgeon is not able to see directlyinto the patient. Thus, the video camera serves as the surgeon's eyes.Images of the body interior are transmitted to an external video monitorto allow a surgeon to analyze the images, make a diagnosis, visuallyidentify internal features, and perform surgical procedures based on theimages presented on the monitor.

MIS procedures may involve minor surgery as well as more complexoperations. Such operations may involve robotic and computertechnologies, which have led to improved visual magnification,electromechanical stabilization and reduced number of incisions. Theintegration of robotic technologies with surgeon skill into surgicalrobotics enables surgeons to perform surgical procedures in new and moreeffective ways.

Although MIS techniques have advanced, physical limitations of certaintypes of medical equipment still have shortcomings and can be improved.For example, during a MIS procedure, catheters (e.g., a sheath catheter,a guide catheter, an ablation catheter, etc.), endoscopes orlaparoscopes may be inserted into a body cavity duct or vessel. Acatheter is an elongated tube that may, for example, allow for drainageor injection of fluids or provide a path for delivery of working orsurgical instruments to a surgical or treatment site. In known roboticinstrument systems, however, the ability to control and manipulatesystem components such as catheters and associated working instrumentsmay be limited due, in part, to a surgeon not having direct access tothe target site and not being able to directly handle or control theworking instrument at the target site.

More particularly, MIS diagnostic and interventional operations requirethe surgeon to remotely approach and address the operation or targetsite by using instruments that are guided, manipulated and advancedthrough a natural body orifice such as a blood vessel, esophagus,trachea, small intestine, large intestine, urethra, or a small incisionin the body of the patient. In some situations, the surgeon may approachthe target site through both a natural body orifice as well as a smallincision in the body.

For example, one or more catheters and other surgical instruments usedto treat cardiac arrhythmias such as atrial fibrillation (AF), areinserted through an incision at the femoral vein near the thigh orpelvic region of the patient, which is at some distance away from theoperation or target site. In this example, the operation or target sitefor performing cardiac ablation is in the left atrium of the heart.Catheters are guided (e.g., by a guide wire, etc.) manipulated, andadvanced toward the target site by way of the femoral vein to theinferior vena cava into the right atrium through the interatrial septumto the left atrium of the heart. The catheters may be used to applycardiac ablation therapy to the left atrium of the heart to restorenormal heart function.

However, controlling one or more catheters that are advanced throughnaturally-occurring pathways such as blood vessels or other lumens viasurgically-created wounds of minimal size, or both, can be a difficulttask. Remotely controlling distal portions of one or more catheters toprecisely position system components to treat tissue that may lie deepwithin a patient, e.g., the left atrium of the heart, can also bedifficult. These difficulties are due in part to limited control ofmovement and articulation of system components, associated limitationson imaging and diagnosis of target tissue, and limited abilities anddifficulties of accurately determining the shape and/or position ofsystem components and distal portions thereof within the patient. Theselimitations can complicate or limit the effectiveness of surgicalprocedures performed using minimally invasive robotic instrumentsystems.

For example, referring to FIG. 1, a typical field of view or display 10of a catheter includes a representation 12 of a catheter and an image 14of a catheter. The catheter representation 12 is in the form of “cartoonobject” that is created based on a position of the catheter determinedaccording to a kinematics model. The image 14 is generated using animaging modality such as fluoroscopy.

A kinematics model is related to the motion and shape of an instrument,without consideration of forces on the instrument that bring about thatmotion. In other words, a kinematics model is based on geometricparameters and how a position of the instrument changes relative to apre-determined or reference position or set of coordinates. One exampleof a kinematics model that may be used in non-invasive roboticapplications receives as an input a desired or selected position of theinstrument, e.g., a position of a distal portion of the instrumentwithin a portion of the heart, and outputs a corresponding shape orconfiguration of the instrument, e.g., with reference to a current orknown shape or configuration, that results in positioning of theinstrument according to the input.

A fluoroscopic system may be utilized to image, or “visualize”, theelongate instrument or a portion thereof. A drawback of knownfluoroscopic imaging systems is that it they are projection based suchthat depth information is lost. As a result, true three-dimensionallocation of objects such as an elongate instrument in the field of viewof the fluoroscope is lost as a result of generating a two-dimensionalfluoroscopic image. Thus, even if it is possible to obtain accurate x-yor two-dimensional data, it may be difficult or impossible to accuratelydetermine the location of a catheter in three-dimensional space.Examples of fluoroscopy instruments and associated methods are describedin further detail in U.S. application Ser. No. 11/637,951, the contentsof which were previously incorporated by reference.

In the example illustrated in FIG. 1, the shapes of the representation12 and image 14 are generally consistent, but in some applications, theposition and/or shape of a catheter or elongate instrument may differand inaccurately reflect the shape and/or position of the instrument,which may result in complications during surgical procedures. Suchmismatches may be interpreted as a problem associated with thekinematics model or controls or sensing algorithms, or as a result ofcontact between the subject instrument and a nearby object, such astissue or another instrument.

A process called “registration” may be performed to spatially associatethe two coordinate systems in three dimensions. Registration involvesmoving the elongate instrument to one or more positions, imaging theinstrument with one or more positions of the fluoroscopic imaging device(e.g., the C-arm), and analyzing the images to deduce the coordinatesystem of the elongate instrument in relation to the coordinate systemof the fluoroscopic imaging device. This process, however, can betedious, and it is relatively easy for the elongate instrument to go outof alignment relative to the other pertinent coordinate systems.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be readily understood by the followingdetailed description, taken in conjunction with accompanying drawings,illustrating by way of examples the principles of the presentdisclosure. The drawings illustrate the design and utility of preferredembodiments of the present disclosure, in which like elements arereferred to by like reference symbols or numerals. The objects andelements in the drawings are not necessarily drawn to scale, proportionor precise positional relationship; instead emphasis is focused onillustrating the principles of the present disclosure.

FIG. 1 generally illustrates a field of view or display that includes arepresentation of a catheter generated using a kinematics model and animage of a catheter;

FIG. 2A illustrates a surgical apparatus constructed according to oneembodiment that includes an optical fiber sensor attached to or integralwith an elongate surgical instrument;

FIG. 2B is a cross-sectional view of an elongate instrument constructedaccording to one embodiment and that defines a central lumen and a lumendefined through a wall of the catheter in which an optical fiber sensormay be positioned;

FIG. 3A schematically illustrates a system for use with optical fibersensors having one or more Fiber Bragg Gratings written or formedtherein and that are coupled to or integral with one or more componentsof a robotic surgical system;

FIG. 3B illustrates a core of an optical fiber sensor constructedaccording to one embodiment including multiple, axially spaced FiberBragg Gratings;

FIG. 3C illustrates a core of an optical fiber sensor constructedaccording to another embodiment that includes sets of Fiber BraggGratings having different reflectivities;

FIGS. 4A-D illustrate different optical fiber configurations or shapesthat may interface with a portion of an elongate instrument or catheterto prevent twisting of the fiber, and FIG. 4E illustrates anotherconfiguration of an optical fiber sensor that includes off-center core;

FIG. 5 generally depicts a mismatch between a shape of a representationof a catheter generated by a kinematics model and a shape of an image ofa catheter acquired using an imaging modality that can be addressed orprevented with use of optical fiber sensor embodiments;

FIG. 6 generally depicts how optical fiber sensor embodiments may beutilized to provide a more accurate x-y-z position data of atwo-dimensional image of a catheter;

FIG. 7 generally depicts how optical fiber sensor embodiments may beutilized to provide more accurate x-y-z position data and orientation,roll or twist data of a two-dimensional image of a catheter;

FIG. 8 is a flow chart of a method of generating and displaying arepresentation of an instrument body according to one embodiment;

FIG. 9 is a flow chart of a method of controlling movement of acomponent of a robotic surgical system based on shape and locationinformation received or derived from light reflected by an optical fibersensor according to another embodiment;

FIG. 10 is a flow chart of a method of generating a structural map of atissue surface utilizing an optical fiber sensor according to anotherembodiment;

FIG. 11 illustrates an embodiment in which multiple fibers are coupledto or integral with respective robotically controllable catheters thatcarry different types of catheters;

FIG. 12 illustrates another embodiment of a system in which an opticalfiber sensor is coupled to or integral with a controller or instrumentdriver of an elongate instrument;

FIG. 13 illustrates an embodiment in which optical fiber sensors arecoupled to or integral with respective controllers or instrument driversof respective robotically controllable catheters and coupled to orintegral with respective controllable catheters;

FIG. 14 illustrates another embodiment in which optical fiber sensorsare coupled to or integral with elongate instrument bodies such as acatheter and an image capture device;

FIG. 15 illustrates another embodiment of a system in which an opticalfiber sensor is attached or affixed to a patient;

FIG. 16 is a flow chart of a method of performing a calibrationprocedure utilizing an optical fiber sensor according to one embodiment;

FIG. 17 is a flow chart of a method of performing a diagnostic ortherapeutic procedure using an instrument calibrated as shown in FIG.16;

FIG. 18 illustrates one embodiment of a test fixture suitable forcalibration procedures involving an optical fiber sensor;

FIG. 19 illustrates one embodiment directed to establishing a referencegrating or sensor;

FIG. 20 illustrates one embodiment of a connector for providing slackand a grating or sensor reference;

FIG. 21 illustrates an apparatus constructed according to anotherembodiment that is configured to accommodate a grating having a portionof which that is within a sleeve and a portion of which is outside ofthe sleeve;

FIGS. 22A-F illustrate a robotic instrument or surgical system in whichembodiments of the invention may be implemented, wherein FIG. 22Aillustrates a robotic medical instrument system, FIG. 22B illustrates anoperator workstation including a master input device and data gloves,FIG. 22C is a block diagram of a system architecture of a roboticmedical instrument system in which embodiments may be implemented orwith which embodiments may be utilized, FIG. 22D illustrates a setupjoint or support assembly of a robotic instrument system with whichembodiments may be utilized, FIG. 22E is a rear perspective view of aflexible catheter assembly of a robotic instrument system with whichembodiments may be utilized, and FIG. 22F illustrates an instrumentdriver to which the flexible catheter assembly illustrated in FIG. 22Emay be attached and to which an optical fiber sensor may be coupled;

FIGS. 23A-C are different views of a multi-a sheath catheter having anoptical fiber sensor coupled thereto according to on embodiment;

FIGS. 24A-D are different views of a rotatable apparatus that interfaceswith the sheath catheter illustrated in FIGS. 23A-C;

FIGS. 25A-F are different views of an orientation platform or interfacefor a working instrument with which rotational apparatus embodiments asshown in FIGS. 24A-D can be utilized;

FIGS. 26A-B illustrate other configurations of a robotic instrumentsystem in which embodiments may be utilized, wherein FIG. 26Aillustrates an embodiment including three multi-segment sheathcatheters, each of which has an optical fiber sensor coupled thereto,and FIG. 26B shows the configuration shown in FIG. 26A with anadditional optical fiber sensor coupled to an image capture device thatextends through the master sheath;

FIGS. 27-43 illustrate aspects of a control schema, kinematics,actuation coordinates for kinematics, and a block diagram of a systemwith which embodiments may be implemented or utilized, a sampleflowchart of transforming a position vector to a haptic signal, and ablock diagram of a system including haptics capability of roboticsurgical systems in which embodiments of the invention may beimplemented; and

FIGS. 44-49 illustrate a system and system configuration forvisualization of tissue by overlaying images, a schematic for overlayingobjects to the display, a distributed system architecture and hardwareand software interfaces of robotic surgical systems in which embodimentsmay be implemented.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the present disclosure, aninstrument system that includes an elongate instrument body and anoptical fiber sensor is provided. The optical fiber sensor includes anelongate optical fiber that is coupled to the elongate instrument body,wherein a portion of the optical fiber is coupled to the elongateinstrument body in a manner to provide slack in the fiber to allow foraxial extension of the elongate instrument body relative to the opticalfiber.

According to another embodiment of the present disclosure, an instrumentsystem that includes an elongate instrument body and an optical fibersensor is provided. The elongate instrument body includes asubstantially rigid proximal portion and a flexible distal portion. Theoptical fiber sensor includes an optical fiber that is coupled to theelongate instrument body, wherein a portion of the optical fiber iscoupled at a known reference location on the proximal portion of theelongate instrument body.

According to yet another embodiment of the present disclosure, aninstrument system that includes an elongate instrument body and anoptical fiber is provided. The optical fiber is coupled to the elongateinstrument body, wherein at least one of the optical fiber and theelongate instrument body has a structural attribute that preventstwisting of the optical fiber relative to the elongate instrument body.

These and other aspects of the present disclosure, as well as themethods of operation and functions of the related elements of structureand the combination of parts and economies of manufacture, will becomemore apparent upon consideration of the following description and theappended claims with reference to the accompanying drawings, all ofwhich form a part of this specification, wherein like reference numeralsdesignate corresponding parts in the various figures. In one embodiment,the structural components illustrated can be considered are drawn toscale. It is to be expressly understood, however, that the drawings arefor the purpose of illustration and description only and are notintended as a definition of the limits of the present disclosure. Itshall also be appreciated that the features of one embodiment disclosedherein can be used in other embodiments disclosed herein. As used in thespecification and in the claims, the singular form of “a”, “an”, and“the” include plural referents unless the context clearly dictatesotherwise.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Embodiments of the invention are related to systems, apparatus andmethods including or involving the use of optical fiber sensors, e.g.,Fiber-Bragg sensors, which may be used to provide accurate shape and/orposition data of an elongate instrument.

Referring to FIG. 2A, according to one embodiment, one or morecomponents of a robotically controlled instrument 200 of a roboticsurgical system include an optical fiber or fiber sensor 215 (referredto as optical fiber sensor or fiber 215), which is coupled to, or anintegral part of, an elongate instrument body 210. Data based on lightreflected by gratings of the fiber 215 may be used to determine theshape and/or position of the elongate instrument, which may be acatheter, such as a guide catheter. In the illustrated embodiment, theelongate instrument or catheter 210 is a part of a roboticallycontrolled instrument 200 that it utilized to position a bendable distalend portion 211 of the catheter 210 and one or more working instruments240 at a target site within a patient. The particular working instrument240 employed may depend on the target tissue and manner in which theinstrument 200 is inserted or advanced into the patient.

The optical fiber sensor 215 can be attached or coupled to an elongateinstrument or catheter 210 in various ways. Referring to FIG. 2B, in oneembodiment, the optical fiber sensor 215 extends through a central orother lumen 217 defined by the catheter 210. According to anotherembodiment, the optical fiber sensor 215 extends through a lumen 213defined through a wall of the catheter 210, i.e., through a lumen 213defined between an inner wall 214 and an outer wall 216 of the catheter210. FIG. 2B illustrates a single lumen 213 defined within a catheter210 wall to accommodate a single optical fiber sensor 215 and a singlelumen 217, but in other embodiments, multiple lumens 213, 217 may bedefined, and an optical fiber sensor 215 may extend through some or allof the multiple lumens 213, 217. In other embodiments, the optical fibersensors 215 can be coupled, bonded or attached to the inner wall 214 orto the outer wall 215 as appropriate. The inner wall 214 may also definea groove in which a fiber 215 may be positioned. In yet otherembodiments, an optical fiber sensor 215 can be coupled to or integralwith an outer surface 216 using, for example, a suitable adhesive orbonding agent and/or the fiber 215 may be positioned within an apertureor groove that is formed within the outer wall 216. Further, the opticalfiber 215 can be coupled to a catheter or other instrument 210 in such amanner that a portion of the optical fiber 215 is coupled at a knownreference location on the proximal potion of the instrument 210.

For ease of explanation, this specification refers to an optical fibersensor 215 that is coupled to or integral with a catheter 210 or othersystem component in a non-limiting manner. Thus, while certain figuresmay illustrate an optical fiber sensor 215 extending along a surface ofa catheter 210 for ease of illustration, it should be understood that inpractice, one or multiple optical fiber sensors 215 may extend throughone or more lumens 213, 217 of one or more instruments depending on theconfiguration employed.

Referring again to FIG. 2A, one manner in which robotic intravascularsystems including an elongate instrument 210 having an optical fibersensor 215 coupled thereto or integral therewith may be utilized is toposition the catheter 210 or other working instrument 240 within theheart 230, e.g., to diagnose, treat or ablate endocardial tissue. In theillustrated application, a robotically controlled instrument 200including a catheter or guide instrument 210 and a sheath instrument 220is positioned within the heart 230. FIG. 2A depicts delivery of theinstrument 200 utilizing a standard atrial approach in which therobotically controlled catheter 210 and sheath 220 pass through theinferior vena cava and into the right atrium. An image capture device(not illustrated in FIG. 2), such as an endoscope or intracardiac echo(“ICE”) sonography catheter (not shown in FIG. 1), may be advanced intothe right atrium to provide a field of view upon the interatrial septum.The catheter 210 may be driven to the septum wall 132, and the septum132 may be crossed using a conventional technique of first puncturingthe fossa ovalis location with a sharpened device, such as a needle orwire, passed through a working lumen of the catheter 110, then passing adilator or other working instrument 240 over the sharpened device andwithdrawing the sharpened device to leave the dilator 240, over whichthe catheter 210 may be advanced.

Various working instruments 240 (not shown in FIG. 1) may be deliveredthrough the lumen of the catheter 210 as necessary and depending on thesurgical application. For example, for treatment of atrial fibrillation,the working instrument 240 may be an ablation catheter that deliverstargeted radio frequency (RF) energy to selected endocardial tissue.Further aspects of such systems, devices and applications are describedin U.S. application Ser. No. 11/176,598, the contents of which werepreviously incorporated herein by reference.

An optical fiber sensor 215 may be used in various applications and maybe coupled to or integral with various instruments and surgical systemcomponents, and even a patient. For example, in one embodiment, theoptical fiber sensor 215 serves as a localization sensor, which may beused to “localize” or monitor the position and/or orientation of variousobjects or system components involved in a surgical procedure. Theoptical fiber sensor 215 may also be utilized in other applicationsinvolving registration, calibration, force calculation and feedback,improved accuracy, mechanical interfacing or “connectorization,” andfiber-based diagnostics. Further aspects of embodiments of the inventionand systems in which embodiments may be utilized are described infurther detail with reference to FIGS. 3A-49.

Referring to FIG. 3A, an optical fiber sensor 215 constructed accordingto one embodiment includes a fiber core 304 surrounded by a cladding306. The core 304 includes a distributed Bragg reflector, such as one ormore Fiber Bragg gratings or FBGs 302 (generally referred to as FBGs orgratings 302), which are formed within or written into the core 304.FBGs 302 can be inscribed or written into the core 304 of a fiber 215,e.g., in a periodic manner, using various known methods and devices. Forexample, an ultraviolet (UV) laser may be used to “write” a periodicvariation of refractive index (n) into the core 304 of a photosensitivegermanium-doped silica fiber. Various types and arrangements of FBGs 302may also be utilized in embodiments including, for example, uniform,chirped, tilted, superstructure, uniform positive-only,Gaussian-Apodized Index FBGs. For ease of explanation, thisspecification refers generally to one or more FBGs 302 generally, but itshould be understood that different numbers, types and arrangements ofFBGs 302 may be utilized in embodiments, and that various systemcomponents may include fibers 215 so configured.

FIG. 3A illustrates a single fiber 215 and a single FBG 302 written onor within the core 304. In other embodiments (e.g., as generallyillustrated in FIGS. 3B-C), an optical fiber sensor 215 may have a fibercore 304 that includes multiple FBGs 302 or sets thereof that areaxially distributed along the core 304. In certain embodiments, the FBGs302 may be continuous, overlapping or partially overlapping.

In one embodiment, as illustrated in FIG. 3C, a core 304 may includedifferent sets 361-362 of FBGs 302 that have different reflectivities.Although FIG. 3C illustrates sets 361, 362 having three FBGs 302 forpurposes of illustration, it should be understood that different numbersof gratings may be utilized, and the number of gratings 302 in each set361, 362 may be the same or different. For example, in the illustratedembodiment, the reflectivity of the first set 361 of FBGs 302 may beconfigured to have relatively low reflectivity, whereas another set 362has slightly higher reflectivity. In one embodiment, a first fiber 215may include gratings of a first reflectivity, and a second fiber 215 mayinclude gratings of a second, different reflectivity.

In another embodiment, a single fiber 215 has FBGs 302 of differentreflectivities, which may be suitable for use with both opticalfrequency domain reflectometry (ODFR) and wavelength divisionmultiplexing (WDM) processors that are operably coupled to the samefiber 215. In this manner, embodiments combine the advantages of twodifferent processing systems. OFDR is suited for low reflectivelygratings 302 of the same wavelength and is beneficial since it may beable to handle a larger number of gratings per length of fiber 215compared to WDM, whereas WDM is suited for high reflectivity gratings302 of different wavelengths, and can achieve high signal-to-noiserations. Thus, embodiments may advantageously utilize both OFDR and WDMon the same fiber 215. Further aspects of OFDR and WDM processing aredescribed in U.S. application Ser. No. 12/106,254, the contents of whichwere previously incorporated herein by reference.

Thus, various figures, including FIGS. 3A-C, are provided as examples ofhow FBGs 302 may be arranged, and it should be understood that variousnumbers and arrangements of FBGs 302 may be utilized, that the FBGs 302may have the same or different reflectivities. Further, while FIG. 3Aillustrates a fiber 215 having a cylindrical shape, other fiber 215configurations and shapes can be utilized, and the outer surfaces offibers 215 may be configured or have structural attributes (e.g., shapesor other structural features) to interface with an inner surface orcorresponding structural attribute of a catheter 210 or other instrumentto form a key-like arrangement that limits or prevents twisting orrotational movement of the fiber 215 within the catheter 210.

For example, referring to FIG. 4A, in one embodiment, an optical fibersensor 215 has an oval-shaped outer surface 402. An inner surface of acatheter 210 may have a corresponding oval shape to mechanically limitor prevent twisting of the fiber sensor 215 within the catheter 210.According to another embodiment, referring to FIG. 4B, a fiber sensor215 is configured such that it includes an arcuate or cylindrical outersurface 404 and a linear or flat outer surface, segment or beveled edge406. Although one flat segment 406 is illustrated, a fiber sensor 215may include other numbers of segments, which may be arrangedsymmetrically or asymmetrically. An inner surface of a catheter 210 mayhave a shape corresponding to the surface shown in FIG. 4B to limit orprevent rotation of the fiber sensor 215. Referring to FIG. 4C, in afurther embodiment, an optical fiber sensor 215 may also comprisemultiple fibers, e.g., two fibers 215 a, 215 b, which have mating faces406 a, 406 b and respective cylindrical surfaces 404 a, 404 b to form ashape that resembles the number 8. Although FIG. 4C illustrates twofibers 215 a, 215 b, other numbers of fibers 215 may be configured tointerface with each other with corresponding faces or edges 406 or otherinterfacing surfaces resulting in other shapes. An inner surface of acatheter 210 may have a shape corresponding to this outer surface toprevent or limit twisting or rotation of the fibers 215 a, 215 b.Referring to FIG. 4D, according to another embodiment, an optical fibersensor 215 may have an edge 406 (as shown in FIG. 4B) and a deepergroove 408 formed therein. An inner surface of a catheter 210 may have acorresponding segment or protrusion configured to mate with the groove408 to avoid twisting or rolling between the fiber 215 and the catheter210. Although the groove 408 is shown as having a rectangular shape,other shapes may also be utilized, e.g., V-shaped grooves and othershaped grooves. Further, while embodiments are described with referenceto an optical fiber 215 being disposed within an instrument such as acatheter 210, embodiments may also be applied to a fiber that is coupledto an outer surface of an instrument.

Additionally, each fiber 215 may contain a single core or comprisemultiple sub-cores. In a further embodiment, referring to FIG. 4E, theoptical fiber sensor 215 may include an “off-center” single core 304,which may be beneficial since the shape of the fiber 215 having one core304 can be calculated under constrained conditions knowing the rollorientation axial strain on the catheter 210.

Further, while figures illustrate certain core 304 and FBG 302configurations and arrangements, embodiments may utilize a singleoptical fiber 215 having one FBG 302, a single optical fiber 215including a multiple FBGs 302 distributed along the core 304, multiplefibers 215, each of which includes one FBG 302, multiple fibers 215,each of which includes multiple FBGs 302 distributed along respectivecores 304, or multiple fibers 215, some of which have only one FBG 302,and others that include multiple FBGs 302, and the FBGs may have thesame or different reflectivities.

Certain fibers 215 may also be different sizes. According to oneembodiment, the diameter of a fiber 215 configured for insertion into apatient is smaller than the diameter of a fiber 215 that is utilizedexternally of the patient. For example, the diameter of a fiber 215intended for insertion into a patient may have a diameter of about 150microns, and a diameter of a fiber 215 intended for use outside of thepatient may have a diameter of about 200 microns or greater, e.g. about500 microns.

Embodiments utilizing a fiber core 304 having a distribution ofaxially-spaced Bragg gratings 302, which may, for example, be continuousor substantially continuous FBGs 302 written on the at least one fibercore 304, provide for various control options. In one embodiment, acontroller 340 of the output unit or readout system 300, or a controlleror computer of the robotic surgical system, or combination thereof, isconfigured to sample the respective FBGs 302 while selected gratings 302are sampled more frequently than others. For example, gratings 302 thatare sampled more frequently may be located on a portion of the Braggsensor optical fiber 325 coupled to a distal end portion of theinstrument 210. Further, the controller 340 can be configured toactively change which Bragg gratings 302 are selected for more frequentsampling based upon, for example, movement of the instrument 210. In yetanother embodiment, the controller 340 may be configured to identify amost proximal Bragg grating 302 that is selected for more frequentsampling based on a detected increase in signal amplitude from therespective grating 302 as compared to more proximal gratings 302.

Additionally, embodiments may involve instruments 210 having multipleoptical fiber sensors 215, each of which has cores 304 havingaxially-spaced Bragg gratings 302. The controller 340 may be configuredto sample respective sensor gratings 302 on the fiber cores 304, and toconduct common mode error analysis by comparing signals received fromrespective corresponding gratings 302 thereon. As an example of commonmode analysis, first and second Bragg sensor optical fibers 215 may beattached to the same elongate instrument 210 in an identical mannerexcept that the fibers 215 may be attached at different locations. Forexample, the first and second fibers 215 may be attached diametricallyopposite each other of an elongate instrument 210 that has the shape ofa cylinder. In this example, through analysis of the signals 236reflected from each fiber 215, the location of the tip of the cylindercan be determined The signals 236 from both fibers 215 can be averagedtogether taking into account that the fibers 215 are a known distanceaway from each other, and noise in the measurement can thus be reducedin this manner.

Referring again to FIG. 3A, in the illustrated system configuration,light emitted 322 by a light source 320, such a laser, is directed intothe fiber core 304 through one or more suitable interfaces, couplers orconnectors (generally illustrated as 328), and transmitted through thefiber core 304 to one or more FBGs 302. Light 322 may be partiallytransmitted 324 through the one or more FBGs 302, and partiallyreflected 326. Reflected light 326 propagates in the opposite directionthrough the core 304, through one or more suitable interfaces, couplersor connectors 328, and is detected by a detector 330 of an output orread out unit (generally identified as 300). The connectors 328 areconfigured to serve as interfaces between one or more fibers 215 and oneor more output or read out units 300.

As shown in FIG. 3A, a control element 340 is located in the output unit300. In another embodiment, a controller 340 is located in controller orcomputer of a robotic surgical system (e.g. as shown in FIGS. 22A-C).The output unit 300 may also be integrated within or a part of acontroller or computer of a robotic surgical system. In a furtherembodiment, a controller 340 includes components of the output unit 300and another computer or controller of a robotic surgical system that areoperably coupled together. For ease of explanation, reference is madegenerally to a controller 340, but it should be understood that thecontroller may be a standalone component or multiple components that areoperably coupled together.

In certain embodiments, the controller 340 is configured forapplications involving shape, position and/or orientation of roboticsurgical system components, calibration, therapeutic, diagnostic andlocalization procedures. The controller be implemented as hardware,software or a combination thereof, and may be processor, amicro-controller, or a computer, which is part of, or associated with,the read out unit 300 or a robotic surgical system. The controller mayprocess reflected light 326 and issue controls in response thereto,e.g., to adjust the shape or reposition of an instrument of a roboticsurgical system (as generally illustrated in FIG. 3A), or generaterepresentations of system components on a display.

It should be understood that the system configuration illustrated inFIG. 3A is provided to generally illustrate system components and howthey may be generally configured, and that other components andconfigurations may be utilized. For example, although FIG. 3Aillustrates a single fiber sensor 215, multiple fiber sensors 215 mayalso be utilized together with additional system components asnecessary. Further, each fiber sensor 215 may have a dedicated detectoror output unit 330 or fibers 215 may share a detector or output unit330. Further, although FIG. 3A illustrates a separate light source 320and output or read out unit 300, the light source 320 may also be a partof the output unit 300 (represented by dotted line). Other systemconfigurations and/or components may be utilized, examples of which aredescribed in further detail in U.S. patent application Ser. Nos.11/678,001, 11/678,016 and 11/690,116 and U.S. Provisional ApplicationNos. 60/785,001 and 60/788,176, the contents of which were previouslyincorporated by reference. Accordingly, FIG. 3A is provided to generallyillustrate system components and how they may be implemented in arobotic surgical system, but other numbers and configurations andcomponents may be utilized as necessary.

FIG. 5 illustrates one example of a situation that embodiments anoptical fiber sensor 215 and related systems and methods are capable ofaddressing or preventing. As shown in FIG. 5, a mismatch between a shapeof a representation 12 of a catheter 210, which may be generated using akinematics model, and a shape of an image 14 of the catheter 210, whichmay be generated using fluoroscopy, is displayed 10. Embodiments of anoptical fiber sensor 215 are coupled to or integral with a catheter 120and address or prevent these types of mismatches by providing accuratecatheter 210 shape data, thereby allowing for accurate manipulation andpositioning of the distal portion 211 of the catheter 210. Embodimentsmay also be utilized to provide accurate position data.

For example, referring to FIG. 6, according to one embodiment, anoptical fiber sensor 215 including one or more FBGs 302 as describedpreviously is coupled to or integral with a catheter 210 and used as alocalization sensing device to determine and display position of a givenpoint upon an instrument 210 on a display 350. In the illustratedembodiment, a two-dimensional image 14 is generated using fluoroscopyand displayed 350. The image 14 may be shown independently (as shown inFIG. 6), or together with other representations and/or images. In oneembodiment, the image 14 is displayed together with the virtual catheterrepresentation 12 or “cartoon object” that is generated according to akinematics model (as described with reference to FIG. 1).

As shown in FIG. 6, embodiments are used as a localization sensingdevice to generate three-dimensional position data or spatialcoordinates (x-y-z) 602 of a given point on the catheter 210. In thismanner, the image 14 is presented with more accurate x-y data, and zdata is also generated such that a location of the catheter 210 ordistal portion 211 thereof can be accurately determined or extractedfrom the optical fiber sensor 215 data. In this manner, a user orsurgeon can know precisely where the distal portion 211 or tip of thecatheter 210 relative to surrounding tissue.

Referring to FIG. 7, in another embodiment, in addition to the accuratex-y-z data 602 (as described with reference to FIG. 6), orientation,roll or “twist” angle data (α, β) 702 may also be determined orextracted from the optical fiber sensor 215. In this manner, embodimentsmay be used to provide position (x, y, z) 602 and orientation (α, β)data 702, which may be particularly beneficial when the distal tip ofthe instrument 210 is at or adjacent to a target area or tissue.

Thus, referring to FIG. 8, one embodiment is directed to a method 800 ofgenerating and displaying a representation of an instrument body 210 andincludes positioning the instrument body 210 within the patient at stage805, and directing light 322 through an optical fiber sensor 215attached thereto or integral therewith at stage 810. At stage 815, light326 is reflected by, e.g., a FBG 302, that is formed within a core 304of the optical fiber sensor 215. At stage 820, reflected light 326 issensed or detected by a detector 330, which may, for example, be a partof or operably coupled to a controller or output unit 300. At stage 825,a controller 340 or other suitable control element operably coupled tothe detector 330 or read out unit 800 is configured to process dataassociated with the reflected light 326 to generate data such as spatialposition and/or orientation data. At stage 830, an image 14 and/or otherrepresentation 12 of the instrument body 210 is generated and displayed350. The shape and/or position of the instrument 210 is accuratelydepicted in, for example, an image 14, based on data determined orderived from the light reflected 326 by FBGs 302 of the optical fibersensor 215. Embodiments may also be utilized for other methods and mayinvolve generating of an image 14 and another representation 12.

Given the number of points along a given instrument 210 that may besensed with a Bragg grating fiber 215, embodiments advantageously allowfor accurate sensing of the shape and/or position of the instrument 210.Shape recognition algorithms, which may be configured to detect theposition of radioopaque markers positioned upon the elongate instrument210, for example, may also be utilized to detect the position of theinstrument 210 in space automatically. In the event of a mismatchbetween the Bragg grating fiber 215 based cartoon object 12 and thefluoroscopic images 14 (e.g., depending on the accuracy of the Bragggating fiber 215 positioned along the elongate instrument 210 and theaccuracy of shape recognition, or marker recognition algorithms), aprocedure may be interpreted. For example, a robotic drive motor may bedeactivated automatically, or subsequent to a notification (audible,visual, etc.) to the operator that a mismatch exists.

The position and/or orientation of other components may also bedisplayed, and they may be displayed 350 together with a representation12 generated according to a kinematic model (as discussed above) and/orwith other representations or images, e.g., together with an indicatorof an orientation of an image capture device, such as an actual orvirtual camera, ultrasound image capture device, optical or infraredimaging chip, etc. In the illustrated embodiment, the orientation of animage capture device is represented as an arrow object 710. The arrowobject 710 indicates the origin position and vector of the orientationof the image capture device relative to other objects presented upon thesame display in two or three dimensions. In other embodiments, thedisplay element depicting roll can be a display of roll angle, oranother arrow, a horizon indicator, etc. Thus, it should be understoodthat additional “cartoon” objects or representations showing theposition and/or orientation of different types of system components canbe displayed together with the representation 510 of an instrument 210based upon localization information.

Further, other localization sensors can be used to determine the shape,position and/or orientation of one or more points of an elongateinstrument, such as a catheter 210, in space—and such points may beutilized to construct and display a cartoon or representation of suchinstrument 210 relative to other images of the same object, generatedbased upon fluoroscopy, other models, etc. For example, otherlocalization sensors may be coupled to an instrument body such as acatheter 210 and/or coupled to a fiber 215. Thus, a catheter 210 mayinclude an attached fiber 215 and localization sensor, or thelocalization sensor may be coupled to the fiber 215 instead. Suitablelocalization sensors that may be used for this purpose include, forexample, electromagnetic coils (such as those available from BiosenseWebster or Ascension Technology), potential difference sensing devices(such as those available from St. Jude Medical), and ultrasound sensors.Further aspects of such devices are described in further detail in U.S.application Ser. No. 11/637,951, the contents of which were previouslyincorporated by reference.

Thus, embodiments of optical fiber sensors 215 can be used to “localize”or monitor the positions and/or orientations of, various objects orsystem components involved in a particular procedure. For example, notonly is it useful to localize instruments, e.g., a catheter 210,configured and utilized for endocorporeal use in a given procedure, butalso it is useful to localize other associated objects and components,such as structures utilized to present the operational instruments 210into the body, structures utilized to stabilize the body, the bodyitself or portions thereof. Further, depending upon the capabilities(for example bus and processing capabilities; certain localizationsystems are only capable of sensing a small number of sensors inparallel; Bragg Grating sensors 215, on the other hand, may be utilizedto gather at least positional information regarding many points along agiven structure or multiple structures, depending upon the particularsignal processing configuration) of the localization system utilized,multiple mechanically-associated objects may be localizedsimultaneously. For example, the instrument 200 shown in FIG. 2Aincludes three coaxially associated instruments—an outer sheath catheter220, an inner coaxially-associated catheter 210 such as a guidecatheter, and a working instrument 240 such as a guidewire, a pusherwire, an ablation catheter, a laser ablation fiber, a grasper, acollapsible basket tool, etc., which is positioned within the workinglumen defined by the inner catheter 210, and all of which may belocalized simultaneously with embodiments for maximum operator feedbackand system control.

An instrument or component of a robotic surgical system having anoptical fiber sensor 215 can also be used in other methods, and withexternal structures, such as instrument driver structures, proximalinstrument block structures, instrument driver setup structures,fluoroscopy gun and/or arm structures, etc. With embodiments, theseother system components may also be localized and monitored.

Optical fiber sensors 215 can also be coupled or attached to a patient,e.g., to a patients chest. With this configuration, the position of thepatient's chest may be localized to provide the system and operator withthe ability to understand changes in position and, for example, gate orpause activities during deep breaths or body movements, simply warn theoperator with visual, audible, and/or haptic feedback, or facilitaterecalibration of relative positioning between instruments and thepatient, for example. Such techniques may be utilized to present anoperator with pertinent information regarding the position and/ororientation of one or multiple instruments.

For example, it may be useful to present such information for two ormore robotic arms or robotic catheters being utilized in a givenoperational theatre. Further, it may be useful to present suchinformation for one or more imaging device, such as an ultrasoundcatheter. Further, such techniques are highly useful in not onlyelectromechanically-driven instrument scenarios, such as with roboticarms or robotic catheters, but also in manually-actuated instrumentscenarios, where handles and other components are utilized to operateinstruments.

Referring to FIG. 9, another embodiment is directed to a method 900 ofcontrolling an instrument or elongate body, such as the catheter 210,based on the shape and/or orientation of the catheter 210 that isexpected versus the shape and/or orientation actually achieved ormeasured using an optical fiber sensor 215. The method 900 includesreceiving a user command associated with a new or desired location ofthe catheter 210 at stage 905, and allowing the catheter 210 to move atstage 910 according to the command issued or received at stage 905. Atstage 915, a determination is made whether the measured location of thecatheter 210 changed as expected based on the shape and locationinformation received from the optical fiber sensor 215 coupled theretoor integrated therein at stage 920. If so, then at stage 925, a furtherdetermination is made whether the catheter 210 has reached or ispositioned at the commanded or final destination, position ororientation. If so, the method is successful and complete at stage 930.Otherwise, the catheter 210 can be moved further at stage 915 and methodsteps can be repeated as necessary until the final destination has beenreached. However, movement of the catheter 210 may also result in stage920 resulting in a determination that the measured location changed inan unexpected way, in which case a warning may be issued and/or catheter210 movement can be limited or aborted at stage 935.

Referring to FIG. 10, other embodiments are directed to a method 1000 ofgenerating a structural map of an internal body tissue, such asendocardial tissue. The method includes maneuvering a distal end portion211 of an elongate flexible instrument or catheter 210, which includesan optical fiber sensor 215, within an anatomical workspace in a body atstage 1005, and detecting when a distal end 211 of the instrument 210contacts a tissue surface in the workspace at stage 1010. At stage 1015,a geometric configuration of the distal end portion 211 of theinstrument 210 is determined when the distal end 211 contacts the tissuesurface, e.g., based on light reflected 226 by one or more FBGs 302. Atstage 1020, position data is generated and indicative of a position ofthe instrument distal end portion 211 based upon the determinedgeometric configuration of the instrument distal end portion 211 whenthe distal end portion 211 of the instrument 210 contacts the tissuesurface. At stage 1025, one or more or all of the previous stages can berepeated as necessary in order to generate sufficient position data togenerate a structural map of the tissue surface.

Referring to FIG. 11, in another embodiment, multiple roboticallycontrolled catheter instruments 210 a,b may have respective opticalfiber sensors 215 a,b coupled thereto (e.g., extending through a lumen213 or 217). In the illustrated embodiment, one robotically controllablecatheter 210 a has an optical fiber sensor 215 a coupled thereto andcarries or supports an imaging device or imaging catheter 1102. Anotherrobotically controllable catheter 210 b includes an optical fiber sensor215 b and carries or supports a mapping catheter 1104, which is used tomap electrical signals within the heart 330. With this configuration,embodiments advantageously allow the shape and location of multiplecatheters 210 a,b that are used for different purposes to be determinedby use of light reflected by FBGs 302 of respective optical fibersensors 215 a,b.

Yet other embodiments are directed to methods involving systemcomponents other than elongate instruments or catheters. For example,referring to FIG. 12, other systems and associated methods may involvedetermining one or more position and/or orientation variables of aninstrument driver 1200 that includes one or more motors 1205 that can beactuated to controllably manipulate a bendable distal end portion 211 ofan elongate instrument or catheter 210 (which may also have an opticalfiber sensor 215 coupled thereto as illustrated) based on detectedreflected light signals 326 received from the respective FBGs 302 on theoptical fibers 215. FIG. 12 generally illustrates an output or readoutunit/controller 300/340 for ease of illustration, but may includecomponents such as a light source, detector, etc., as discussed withreference to FIG. 3A and FIGS. 22A-C.

Referring to FIG. 13, in a further embodiment, optical fiber sensors 215a,b are coupled to respective robotically controlled catheterinstruments 210 a,b, which may carry or support other devices orcatheters such as an imaging device or imaging catheter 1102 and mappingcatheter as discussed with reference to FIG. 11. Additionally, in theillustrated embodiment, additional optical fiber sensors 215 c,d arecoupled to controllers, arms or instrument drivers 1200 a,b that areused to control or manipulate the respective catheters 210 a,b. Thearms, instrument drivers or controllers 1200 a,b are typically locatedoutside of the patient's body and, in one embodiment, the fiber sensors215 are larger than the fiber sensors 215 that are coupled to cathetersor elongate instruments 210 a,b and advanced into the patient's body.For example, fibers 215 c,d that are located outside of a patient canhave a diameter of greater than 200 microns, e.g. about 500 microns,whereas fibers 215 a,b for use within a patient may have a diameter ofabout 150 microns. With this configuration, larger diameter fibers 215c,d can then have the individual cores spread further apart which, maybe utilized to increase the accuracy of the measurements by increasingthe difference in signal produced by cross-sectionally opposing fibers.The larger diameter fibers 215 c,d can accurately measure the locationof the arm or driver 1200 a,b, and the smaller diameter fibers 215 a,bcan measure from a point where the larger diameter fiber 215 c,d ends.

In another embodiment, referring to FIG. 14, other systems andassociated methods are directed to determining one or more positionand/or orientation variables of an image capture device 1400 based onlight reflected 226 by Bragg gratings 302 on a Bragg sensor opticalfibers 215 b coupled to or integral with the image capture device 1400.Examples of image capture devices 1400 include a fluoroscope, an opticalcamera, an infrared camera, an ultrasound imager, a magnetic resonanceimager, and a computer tomography imager. In the illustrated embodiment,the catheter 210 and the image capture device 1400 are advanced throughan outer sheath 220 and include respective optical fiber sensors 215a,b, but other system configurations may be utilized. A controller 340may be configured to determine one or more position and/or orientationvariables of the image capture device 1400 based on signals 326 receivedfrom Bragg gratings 302 on a fiber 215.

Referring to FIG. 15, other methods and systems are directed to anoptical fiber sensor 215 that is attached to a patient's body 1500, e.g.the chest 1505 of a patient 1500, using a patch or other suitableadhesive. For example, a fiber sensor 215 may be coupled to the patchthat is applied to a patient 1502. Such embodiments are useful fordetermining one or more position and/or orientation variables of thepatient's body 1500 to which an optical fiber sensor 215 is attachedbased on signals reflected 226 by one or more Bragg gratings 302.

This configuration allows for detection of an unexpected movement of apatient 1500 based on signals received from the respective FBGs 302, inresponse to which an output can be generated for the system operator toallow the system operator to adjust the catheter 210 within the patient1500 as necessary, temporarily suspend the procedure, or halt theprocedure. Further, such embodiments area also useful for generating animage of the patient 1500 or such that an image of a patient's body 1500that is displayed can be moved or adjusted according to the movementsensed using the optical fiber sensor 215. Other methods may involvecoordinating diagnostic and/or therapeutic procedures on the patientwith the patient's respiration as determined by light reflected 226 byone or more FBGs 302.

More particularly, as described above, it is desirable to know where thepatient 1500 and the anatomy are located in relation to the catheters orelongate instruments 210. For example, if the patient 1500 unexpectedlymoves, a warning may be generated to reposition the catheter 210 orother components. Thus an automatic, semi-automatic or a manual feedbackloop may be created based on the position of the patient 1500.Embodiments provide for using a shape and location measurement fiber 215for patient 1500 monitoring. A key advantage of embodiments is that asingle technology (in this example a Bragg-grating fiber 215) may beused for locating all the essential components of the environment,although other localization technologies, such as electromagnetic andpotential-difference based localization technologies, may also be used,depending upon the capabilities of the particular system employed.

When navigating, or “driving”, in static image-based (preoperative orintraoperative) models, such as those created utilizing modalities suchas MRI and/or CT, it is advantageous to register the model to the distaltip 211 of the elongate instrument 210; after such registration has beenaccomplished, if the patient 1500 moves, the registration relationshipmay be significantly altered, requiring another registration unlessembodiments as illustrated in FIG. 15 are utilized. With embodiments, apatient localization device which in one embodiment is an optical fibersensor 215 is used to understand the relative geometric/spatialrelationships of the instrument 210 components and patient 1500 in real,or near-real, time, in which scenario registration may be updatedmanually or automatically.

There are several ways to attach the optical fiber sensor 215 to thehuman body 1500. One method involves wrapping fiber sensor 215 aroundthe chest 1505 of the patient 1500. As discussed above, anothertechnique is to attach the fiber sensor 215 to a patient patch, andapplying the patient patch to the chest 1505 of the patient 1500. As thefiber sensors 215 are very thin, the images of the fibers 215 viewed viaan image capture device 1400 such as a fluoroscope generally are notobjectionable. Further, the fiber sensor 215 may be attached to aradio-opaque marker (not illustrated in FIG. 15) such that it ispossible to see the markers and associated fiber sensor 215 clearly in afluoroscopic image. As the exact location of the marker can also bedetermined by the location measurement system of the fiber sensor 215,the location of the marker can thus be known in two coordinatesystems--the coordinate system of the fluoroscopic imaging system 1400and the coordinate system of the shape and location measurement fibersensor 215. This permits a way to spatially associate the coordinatesystem of the fiber sensor 215 with the coordinate system of the imagingsystem 1400.

More particularly, in one embodiment, referring again to FIG. 14, ashape and location measurement fiber 215 is coupled to an externalimaging device 1400 such as a fluoroscope. The knowledge of the locationof the fluoroscope 1400 is advantageous for the combination display ofthe fluoroscopic image and the virtual catheters and for aligning thecoordinate systems of the imaging system 1400, the fiber sensor 215based device and the robot or other control mechanism 1200. This isparticularly true in the embodiment wherein one has a fluoroscopydisplay driving to be instructive to the operator.

Patient 1500 respiration may also be monitored with the fiber 215 basedmeasurement system. As the patient's chest 1505 moves with breathing,the optical fiber sensor 215 attached thereto also moves. Thesemovements can be monitored, and this information can then be fed backinto the robotic navigation system and may be used, for example, toaccurately deliver therapy. Elaborating on this example, in thesituation in which the catheter 210 holds or supports an ablationcatheter, ablation energy can be delivered at the same point in therespiratory cycle or the respiratory and cardiac cycle. This may improvethe accuracy and effectiveness of ablations.

Monitoring patient 1500 respiration and movement can lead to yet anotheradvantage. In many electrophysiology procedures, models of the inside ofthe heart 230 are built by various methods. These models are quitedistinct from images as a model is a parametric representation of theheart 230. These models are often stationary in that they do not containany information about the dynamics of the heart 230 or the dynamics ofthe patient 1500 such as due to respiration. These models are used fornavigation purposes for example to navigate a catheter 210 inside of theheart 320. The availability of patient 1500 movement data (such as viarespiration) though the use of a fiber sensor 215 or other localizationtechnique, advantageously enables compensation or adjustment of themodel.

Embodiments can also be utilized for purposes of registration, or forspatial association of objects and/or images. Such registration may becontinuous or semi-continuous, based on a common reference or connectedby a defined relationship. References may also be connected by a definedrelationship or associated utilizing other imaging modalities.

As discussed above, in known minimally invasive procedures, an elongateinstrument 120 may be inserted within the body and an imaging devicesuch as a fluoroscopic system may be utilized to image, or “visualize”,the elongate instrument 120 or a portion thereof, but a drawback ofknown fluoroscopic imaging systems is that they are projection based—thedepth information is lost and therefore true three-dimensional locationof objects such as an elongate instrument in the field of view of thefluoroscope is lost. However, with embodiments, an elongate instrument210 has a shape and location measuring fiber or optical fiber sensor 215that provides the three-dimensional location of specific locations in acontinuous or semi-continuous manner, thus allowing for automaticregistration. Locations of interest may be visualized with thefluoroscope and spatially analyzed utilizing techniques such as pattern,geometry, shape, movement, and/or marker recognition (preferably withthe help of radioopaque markers positioned upon portions of the subjectinstrument, beacon transducers placed upon the instrument for ultrasoundpinging localization, or other techniques to localize with fluoroscopy);such results then may be processed in conjunction with the locationinformation obtained about these same locations from the fiber sensor215 based measurement device. Image information from the two techniquesmay be utilized to make the images produced by each appropriately andaccurately associated with the other in three-dimensional space.

A Bragg grating fiber sensor 215 based shape and localization measuringdevice may be attached to one or more or all of the key elements in anoperating room environment including, for example, a catheter 210 orother elongate instrument, to controllers or instrument drivers 1200that control the location of the catheter 210, to the bed supporting thepatient 1500, to the patient 1500, and to an image capture device 1400such as an external imaging system, one example of which is afluoroscopic system. It is advantageous if all of the fiber sensors 215in this embodiment have a single common reference point or referencecoordinate system, preferably located as distally as possible withoutcompromising the mechanical behavior of the system (to increase theeffectiveness of common-mode error rejection analysis, which may beapplied to light or data moving through the system of localizationfibers 215). This ensures that the coordinate system for the devices andinstruments and objects to which the fiber 215 based system is coupledare all similarly and precisely spatially associated duringregistration.

Each fiber 215 may have its own reference point, and each referencepoint may refer to a single coordinate system for coordination.Different instruments may each have a fiber 215, and in this case, andthe relationship between different instruments can be determined basedon a fixed spatial relationship between instruments, or if there is nota fixed spatial relationship, then each fiber on each instrument mayrefer to the same coordinate system, and data from the fibers can beused for an necessary adjustments. Thus, with embodiments, the positionand/or orientation variables of a plurality of elongate instruments,each of which includes an elongate instrument body having a Bragg sensoroptical fiber 215 coupled thereto, may be determined and registered in asingle reference coordinate system. The instrument bodies may be coupledto a same or different structure in a known spatial relationship, orcoupled to a same or different structure in an unknown spatialrelationship. In the latter case, registration of the instrumentposition and/or orientation variables of respective instruments in asingle reference coordinate system is accomplished by maintaining afixed distance between respective locations on the instrument bodies.

Even if the references for all of the fiber sensors 215 are not thesame, in one embodiment there is a defined relationship between thedifferent references such that the relationship between the differentcoordinate systems is accurately defined and may be utilized to analyzethe spatial relationships between coordinate systems. For example, tworeferences may be utilized for two fibers 215 attached to two devices,with the two references connected by a stiff structural rod or member(or another device that prevents relative movement between the referencepoints, or with other devices to predictably understand thegeometric/spatial relationship between the two references) to preventrelative motion between the references.

Other technologies such as an electromagnetic orpotential-difference-based localization, lasers or ultrasound (forbeaconing, shape/marker/pattern/etc. recognition, and/or time-of-flightanalysis to determine relative spatial positioning) may be used toestablish the absolute positions of each reference. For example, anelectromagnetic localization sensor may be placed on each Bragg fiber215 to obtain the three-dimensional coordinates relative to a coordinatesystem established by the electromagnetic localization system. Themeasurements provided by each fiber 215 all are consistent with eachother as they all are referenced back to a common reference.

Embodiments may also be utilized in procedures for calibrationinstruments and tools in which the instrument or tool includes anoptical fiber sensor 215. While certain techniques for calibration areknown, embodiments provide apparatus and methods for calibrating arobotically controlled elongate instrument attached to one or more shapeand location measuring fibers 215.

Initial calibration information can be obtained utilizing severaltechniques. In one method, measurement or observation of propertiesand/or behaviors of the instrument having an optical fiber sensor 215and being calibrated are observed. Other methods involve obtaininginformation from the design of the localization/shape-sensing fiber 215,the elongate instrument 210, or both. Yet other methods involve use ofcalibration or test fixtures adapted for an instrument that includes anoptical fiber sensor 215.

Referring to FIG. 16, a calibration procedure 1600 according to oneembodiment includes positioning an instrument or tool in a knowngeometric configuration at stage 1605. At stage 1610, a sensed geometricconfiguration is determined based on signals or light 326 received fromthe one or more Bragg gratings 302 of a fiber sensor 215 while theinstrument body 210 is in the known geometric configuration. At stage1615, the sensed geometric configuration is compared with the knowngeometric configuration. At stage 1620, if necessary, datarepresentative of the comparison is stored on a storage mediumassociated with instrument 210. The storage medium may be, for example,a programmable device, a bar code, a “RFID” device, or a memory dongle,which may be positioned within or coupled to the elongate instrument210, a software of a system component associated with the elongateinstrument 210, or an external device such as an external server, inwhich case retrieval can be performed via a computer network. Thus, inone embodiment, calibration of an instrument 210 that has an opticalfiber position sensor 215 includes performing a predetermined task withthe instrument 210, acquiring measurements or recording relevantinformation, storing such information or derived information, andretrieving such information for use in normal operation.

Referring to FIG. 17, a diagnostic or therapeutic procedure 1700 may beperformed using the instrument calibrated as shown in FIG. 16. At stage1705, the instrument so calibrated is maneuvered within a patient'sbody. At stage 1710, one or more sensed position and/or orientationvariables of the instrument are determined based on signals receivedfrom the one or more FBGs 302 while the instrument is in the patient'sbody. At stage 1715, the sensed position and/or orientation variablesare adjusted based on calibration data, which may be stored in a storagemedium.

The types of information that can be stored (for example, upon a memorychip associated with or coupled to the elongate instrument) as part ofcalibration include but are not limited to, a diameter of a fiber 215 orfiber core 304, a position of a core 304 within a fiber 215, a positionof fibers 215 within or coupled to an elongate instrument 210 or othersystem component, a position of each FBG 302 formed within the core 304,a reflectivity of each FBG 302, thermal characteristics of the fiber215, mechanical properties of the fiber 215 including stiffness, offsetsand gain, and mechanical properties of the combination of the catheter210 and fiber 215 coupled thereto, such as stiffness and position ororientation dependent properties. Calibration information can be storedin various places and devices including but not limited to, aprogrammable device within or coupled to the elongate instrument 210,software of a system component associated with the elongate instrument210, an external device such as an external server in which caseretrieval can be via a computer network, a bar code, a “RFID” device, ora memory dongle.

Initial calibration information for use in embodiments can be obtainedutilizing several methods. In one embodiment, calibration of an elongateinstrument 210 that includes an optical fiber position sensor 215coupled to a distal portion or tip 211 thereof involves driving theelongate instrument 210 to a known position in a well-defined andcharacterized geometric fixture or test structure. The operator thencompares the reading from the sensor 215 to the known position. Thereading can thus be equated to the known position.

FIG. 18 illustrates one embodiment of a test fixture 1800 and associatedmethod that may be used during calibration procedures. In theillustrated embodiment, the test fixture 1800 is made from a rigidmaterial such as glass, plastic or another material in which acalibration groove 1802 can be formed. In the illustrated embodiment,the groove 1802 spans a quarter of a circle or has a bend of about 90degrees. The groove 1802 is configured to accommodate a catheter 210 andan optical fiber sensor 215 coupled thereto or integral therewith toensure that the combination of the catheter 210 and optical fiber sensor215 can both bend with the groove 1802, e.g., at about 90 degrees. Themeasurements from the fiber 215 may be read for this section and anyerror may be calibrated out.

In another embodiment, the rigid structure 1800 may define a linear orstraight groove rather than a groove 1802 at about a 90 degree bend asillustrated in FIG. 18. With this configuration, similar to theembodiment described above, the linear groove is configured toaccommodate the catheter 210 and the optical fiber sensor 215. Duringuse, the combination of the catheter 210 and fiber sensor 215 ispositioned within the linear groove, and readings from each FBG 302 areobtained using a detector or fiber readout unit 330. This establishes a“zero” reading for the combination of the catheter 210 and the opticalfiber sensor 215 and corresponds to a linear or straight shape. Anyother shape will be measured relative to a zero shape.

However, a zero shape does not have to be a straight shape. A zero shapecould be any predefined arbitrary shape. A non-straight zero shape maybe desirable if, for example, a fiber is integrated to a pre-bentcatheter 210 (i.e., the natural shape or the “home” shape of thecatheter is not straight but bent).

Thus, a calibration process may involve placing the catheter 210 andlocalization/shape-sensing fiber 215 in a well-defined rigid structure1800 with a groove, sending light 322 (or other appropriate energy)through the fiber 215, detecting light 226 reflected by one or more FBGs302 within the fiber core 304, obtaining strain values and calculatingshape, storing the strain values or some derived values in a storagedevice identifying this as a “zero” shape.

Calibration procedures and related data can be based on each individualdevice or a group of devices. For example, if it is known that a certaingroup of elongate instruments 210 or fibers 215 has a certain type ofproperty that effected the measurements in certain ways, thisinformation can become part of the calibration information. From groupto group, this information may be different. When the catheter 210 isinstalled, the system can read the serial number of the catheter 210 orsome other form of identification and the correct calibration values canbe utilized.

Embodiments may also be utilized in force calculation and feedbackapplications. Various techniques may be utilized to calculate force atthe distal tip of the catheter 210 or other instrument. One such methodis described in U.S. patent application Ser. No. 11/678,016, “Method ofSensing Forces on a Working Instrument”, filed Feb. 22, 2007, previouslyincorporated by reference herein. A force applied upon an instrument maybe calculated by understanding the shape of the instrument with a loadapplied and utilizing kinematic relationships of the instrument to backout the presumed load applied to the instrument. The calculated load maythen be utilized for force feedback to the operator techniques, such ashaptics, on-screen displays, warnings to the operator, etc. For example,in one embodiment, if the force exceeds a certain value, then a warningmessage may be displayed or other actions may be taken to preventpatient injury; yet another alternative to this scheme is that the levelwhen warnings or other actions are initiated may be anatomy specific;for example, in the ventricles where the walls are thicker, higherforces may be applied without triggering an alarm or response.

As described in the incorporated references regarding fiber-based Braggdiffraction localization, the location measurement at the tip of thelocation measurement fiber 215 depends on component measurementsobtained from each grating 302. In practice, each grating 302 willcontribute a finite amount of error in measurement. The error at the tipis the sum of all errors, i.e., errors are cumulative. It is thusadvantageous to maintain length from the tip to the origin, or thereference, or from where the measurement must be taken, as small aspossible. However, the cores 304 of the optical fibers 215 may havenumerous gratings 302, and the number of gratings 302 may be more thanwhat is required between the tip and the origin. Thus, in oneembodiment, it is not necessary to include all of the gratings 302 forlocation measurements at the tip.

Referring to FIG. 19, in one embodiment, a data acquisition and analysissoftware, which may, for example, reside in a controller or associatedmemory of a computer, MID controller, electronics rack or other suitablecontroller of a robotic instrument system illustrated in FIGS. 22A-C),is configured to pass over, disregard or ignore the first number Ngratings 1902, thereby placing the reference 1904 at the location of theN+1^(th) grating 302. In the illustrated embodiment, the first two FBGs302 are ignored, thereby placing the reference 1904 at the third FBG302, which is also at the beginning or proximal end of catheter 210.This method will provide shapes and location measurements relative tothe location of the reference grating.

In other embodiments, systems and methods are directed to using softwareexecuted by a controller 340 to select a reference FBG 302, ameasurement FBG 302 and/or a length or window of a FBG 302 to bemeasured or analyzed. For example, in one embodiment, the location of areference FBG 302 is fixed at a proximal end of a catheter 210 asdescribed above, and the location where the measurement is to beperformed, or the measurement FBG 302 to be selected, is flexiblycontrolled via software such that the selected measurement FBG 302 maychange during the analysis. Further, whichever FBG 302 is selected at agiven time for measurement, the controller 340 software can also beexecuted to select the length of a selected measurement FBG over whichthe measurement is to be performed. In this regard, the length or windowcan be the entire length of a selected measurement FBG 302, or thelength or window may be a portion or segment thereof. For example, abouthalf of a measurement FBG 302 may be selected for measurement ratherthan the entire FBG 302. Embodiments may be implemented usingcontinuous, overlapping or partially overlapping gratings 302.

If absolute location of the tip is needed, and if the first N FBGs 1902sensors are ignored as shown in FIG. 19, then another independent methodcan be used to obtain the absolute or relative position of the reference1904. This independent method may be another fiber 215 which has it tipat the location of the N+1^(th) FBG 302 on the first fiber 215 is, or itmay be an EM based sensor attached on the location of the N+1^(th) FBG302 or some other device. In all of these cases, the absolute locationof the N+1^(th) FBG 302 is measured or its relative location withanother absolute reference is measured.

Various systems and components may be utilized to implement embodiments,and selection of a FBG 302 as a reference grating or a measurement maybe performed using hardware, software or a combination thereof Examplesof systems and components thereof that may be used with or to implementembodiments are described in further detail in U.S. ProvisionalApplication Nos. 60/925,449 and 60/925,472, filed on Apr. 20, 2007, andU.S. application Ser. No. 12/106,254, filed on Apr. 18, 2008, thecontents of which were previously incorporated herein by reference.

Two fibers may be used for measuring twist, e.g. as described in U.S.Patent Application No. 60/925,449, “Optical Fiber Shape Sensing System”,filed Apr. 20, 2007, previously incorporated herein by reference. Two ormore fibers 215, each of which has a single core or multiple cores, mayalso be used to improve location accuracy. If the geometric or spatialrelationship between the fibers 215 is known and invariant, then theindependent location measurements from each fiber 215 can be averagedtogether resulting in improved signal to noise ratio and thereby resultin improved accuracy. This technique of improving accuracy works if thenoise in each measurement is independent of the noise in the othermeasurements. However, for any measurement system such as the fiberbased measurement system, independent noise will exist. Invariance inthe location of the two fibers 215 may be obtained through suitabledesign.

In many minimally invasive interventional systems, such as those made byHansen Medical, Mountain View, Calif., there exists a disposablecomponent (for example, a catheter) which typically enters a human body,and a non-disposable piece, which may, for example, house the mechanismsto control the disposable component. It may be through these controlsthat navigation of the disposable component is achieved within the body.As described above, according to one embodiment, the instrument 210 ormay be coupled to a shape and location measuring fiber 215.Consequently, the connector(s) between the disposable and non-disposablecomponents are configured to accommodate the catheter 210 and the fiber215.

Embodiments address mechanical aspects associated with use of an opticalfiber sensor 215 in robotic surgical components including at thecoupling point or interface prior to the fiber 215 exiting theinstrument and allows for movement of a fiber 215 within the instrument.This is achieved by providing slack at the proximal end since the distalend is typically positioned within the body, and the fiber 215 wouldprobably be constrained in some fashion at the distal end. In thismanner, embodiments address connection issues involving the catheter orelongate instrument 210 flexing or bending by providing slack to thefiber 215 to prevent breaking or excessive straining of the fiber 215.Such slack or “service loop” can be introduced in various ways.

For example, referring to FIG. 20, in one embodiment, a fiber 215 isshown entering a splayer 2000 through a wall or side 2005 and traversinga path through the splayer 2000 that provides slack 2010. For ease ofillustration and explanation, FIG. 20 is a top view of the interior of asplayer 2000, and the catheter 120 is not shown, but would be positionedto the left of the splayer 2000. If the catheter 210 and fiber 215 moveoutwardly to the left, some of this slack 2010 will be taken up orreduced. Slack 2010 may also be provided in other ways and may beoutside of the splayer 2000.

Embodiments address another issue related to the position of the splayer2000 in relation to the location of a FBG 302 (FBGs are not illustratedin FIG. 20 for ease of illustration), e.g., a first FBG 302(1), althoughnot necessarily the first FBG 302, which serves as a reference FBG 2020.In this embodiment, the reference FBG 2020 is positioned such that itslocation is precisely known. In this manner, the location of thereference FBG 2020 can be precisely known and is suitable for fiberbased location measurement devices that depend on various smallmeasurements that start from or based on the reference. For example, thelocation of a second grating 302 is measured in relation to the firstgrating 302, the location of the third grating 302 is measured inrelation to the second grating 302, and so on. Thus if the absolutelocation of the reference grating 2020 is not known in relation to somecoordinate system, then the absolute position of a second grating 302 orthe position of a third grating 302 or any grating 302 that is beyondthe reference grating 2020 is not known.

In some cases, it may not be necessary to know the absolute positions ofthe gratings 302; it may be only necessary to know the relative locationof the second, third and other gratings 302 in relation to the referencegrating 2020. In both of these cases where the absolute position or therelative position is required, it still is necessary to ensure that thereference grating 2020 does not move, or if it does move, that someadjustment or accommodation is utilized to know the location of thereference grating 2020.

As shown in FIG. 20, a fiber 215 is attached to a wall of the splayer2000, and a grating 302, e.g. a first grating, is placed within thefiber 215 at this “reference” location. This ensures that the referencegrating 2020, the first grating in this example, does not move relativeto the wall of the splayer 2000. Since the splayer 2000 is a rigidcomponent, the location of the reference grating 2020 is preciselyknown.

In an alternative embodiment, referring to FIG. 21, a long first grating2102 is provided. A portion of the grating 2102 is in a rigidly placedsleeve 2104 (which is also rigid). A portion of the grating 2102 ispositioned within the sleeve 2104, and a portion is positioned outsideof the sleeve 2104. In certain embodiments, a multi-core fiber 215 hasmultiple cores 304 that are spaced around the neutral axis of the fiber210. This arrangement ensures that sections of the fiber cores 304outside of the sleeve 2104 that are bent will experience a differentstrain compared to sections of the cores 304 that are inside of thesleeve 2104 and that are linear or straight. Reflected light 226 fromthis grating 2102 contains two peaks. A first peak occurs at a frequencycorresponding to the strain experienced by the portion of the grating2102 that is located outside of the sleeve 2104, and a second peakoccurs at a frequency corresponding to the strain experienced by theportions of the grating 2102 that are located inside of the sleeve 2104.The relative locations and the width of the grating 2104 can be used todetermine the exact position of the reference sensor 2020.

Yet other embodiments involve apparatus and methods for determining theposition of the reference sensor or grating 2020. External sensors, suchas precision linear encoders, electromagnetic localization sensors, orpotential-difference-based localization sensors may be attached at thelocation of the reference sensor 2020. These sensors may then beutilized to provide the location of the reference sensor 2020.

As described above, minimally-invasive interventional and/or diagnosticsystems often involve both disposable components (such as a splayer2000) and non-disposable components (such as a light source orinstrument driver). In such a system, the integrity of the connectionbetween the disposable component and a non-disposable component shouldbe high. For this purpose, an integrity test can be performed byemitting light or a test signal into the disposable component andanalyzing the light reflected there from. For example, the receivedsignal 226 from each grating 302, particularly the first or referencegrating 2020 may be analyzed for various parameters, particularly forintensity. If the intensity is low, then the connector may be bad or theconnection may not have been made properly. A warning can then begenerated to warn the operator to check the connection.

In a robotic surgical system that controls a minimally invasive elongateinstrument or catheter 210, it is important to maintain the structuralintegrity of the instrument 210. If, for example, mechanisms thatcontrol the navigation of the elongate instrument 210 break, then thecontrollability of the system may be compromised. To address theseissues, in one embodiment, a fiber 215 is attached to an elongateinstrument or catheter 210 to monitor such mechanical breakages. As thefiber 210 based shape and location measurement device is attached to theelongate instrument or catheter 210, the shape of the instrument orcatheter 210 can be monitored. If the shape is anomalous in some wayindicating a breakage, then a warning is generated for the operator andthe procedure may be stopped manually or automatically.

Having described various apparatus and method embodiments in detail,further details of a robotic surgical systems and components thereof inwhich embodiments of the invention may be implemented are described withreference to FIGS. 22A-26B, and FIGS. 23A-B and 26A-B illustrate howembodiments of the invention can be implemented and including variouscomponents of the robotic surgical system described. A description asystem and methods for utilizing localization data for closed-loopcontrol of a robotic catheter system in which embodiments may beimplemented is provided with reference to FIGS. 22A-25F.

Referring to FIGS. 22A-F, one example of a robotic surgical system 2200in which embodiments of the invention that utilize an optical fibersensor 215 may be implemented includes an operator work or controlstation 2205, which may be configured as, or include control, processoror computer software and/or hardware, which may perform various dataprocessing functions on data from an optical fiber sensor 215 andexecute various processing and control functions in response thereto.

The workstation 2205 is located remotely from an operating table 2207,an electronics rack 2210, a setup joint mounting brace 2215, andmotor-driven controller 1200 in the form an instrument driver 2220. Asurgeon or operator 2225 seated at the operator workstation 2205monitors a surgical procedure, patient 1500 vitals, and controls one ormore flexible catheter assemblies that may include acoaxially-associated instruments of an outer sheath catheter 220, aninner coaxially-associated catheter 210 such as a guide catheter, and aworking instrument 240 such as a guidewire, a pusher wire, an ablationcatheter, a laser ablation fiber, a grasper, a collapsible basket tool,etc., which is positioned within the working lumen defined by the innercatheter 210.

Although the various components of the system 2200 are illustrated inclose proximity to each other, components may also be separated fromeach other, e.g., in separate rooms. For example, the instrument driver2220, the operating table 2207 and a bedside electronics box may belocated in the surgical area, whereas the operator workstation 2205 andthe electronics rack 2210 may be located outside of the surgical areabehind a shielded partition. System 2200 components may communicate withother components via a network, thus allowing for remote surgery suchthat the surgeon 2225 may be in the same or different building orhospital site. For this purpose, a communication link may be provided totransfer signals between the operator control station 2205 and theinstrument driver 2220. Components may be coupled together via cables2230 as necessary for data communication. Wireless communications mayalso be utilized.

Referring to FIG. 22B, one suitable operator workstation 2205 includes aconsole having one or more display screens 2232, which may serve asdisplay 340, a master input device (MID) 2234 and other components suchas a touchscreen user interface 2236, and data glove input devices 2238.The MID 2234 may be a multi-degree-of-freedom device that includesmultiple joints and associated encoders. MID 2234 software may be aproprietary module packaged with an off-the-shelf master input devicesystem, such as the Phantom® from SensAble Technologies, Inc., which isconfigured to communicate with the Phantom® Haptic Device hardware at arelatively high frequency as prescribed by the manufacturer. Othersuitable MIDs 2234 are available from suppliers such as Force Dimensionof Lausanne, Switzerland. The MID 2234 may also have haptics capabilityto facilitate feedback to the operator, and software modules pertinentto such functionality may be operated on the master computer. An exampleof data glove software 2244 is a device driver or software model such asa driver for the 5DT Data Glove. In other embodiments, software supportfor the data glove master input device is provided through applicationdrivers such as Kaydara MOCAP, Discreet 3D Studio Max, Alias Maya, andSoftImage|XSI.

The instrument driver 2220 and associated flexible catheter assembly andworking instruments may be controlled by an operator 2225 via themanipulation of the MID 2234, data gloves 2238, or a combination ofthereof. During use, the operator 2225 manipulates a pendant and MID2234 to cause the instrument driver 2220 to remotely control flexiblecatheters that are mounted thereon. Inputs to the operator workstation2205 to control the flexible catheter assembly can entered using the MID2223 and one or more data gloves 2238. The MID 2234 and data gloves2238, which may be wireless, serve as user interfaces through which theoperator 2225 may control the operation of the instrument driver 2220and any instruments attached thereto. It should be understood that whilean operator 2225 may robotically control one or more flexible catheterdevices via an inputs device, a computer or other controller 340 of therobotic catheter system 2200 may be activated to automatically positiona catheter instrument 210 and/or its distal extremity 211 inside of apatient 1500 or to automatically navigate the patient anatomy to adesignated surgical site or region of interest.

Referring to FIG. 22C, a system architecture of a robotic cathetersystem 2200 includes a controller 340 in the form of a master computer2241 that manages operation of the system 2200. The master computer 2241is coupled to receive user input from hardware input devices such as adata glove input device 2238 and a haptic MID 2234. The master computer2241 may execute MID hardware or software 2243, data glove software 2244and other software such as visualization software, instrumentlocalization software, and software to interface with operator controlstation buttons and/or switches. Data glove software 2244 processes datafrom the data glove input device 2238, and MID hardware/software 2243processes data from the haptic MID 2234. The master computer 2241 oranother computer or controller may also receive data from an opticalfiber sensor 215.

For example, in one embodiment, in response to the processed inputs,e.g., in response to the data or analysis of such data of detectedreflected light signals 326 from the optical fiber sensor 215, themaster computer 2241 processes instructions to instrument drivercomputer 2242 to activate the appropriate mechanical response from theassociated motors and mechanical components of the driver 2220 toachieve the desired response from the flexible catheter assemblyincluding a sheath 220 and catheter or elongate instrument 210.

Further, in another embodiment, the master computer 2241 or othersuitable computer or controller may control actuation of the at leastone servo motor to activate the appropriate mechanical response from theassociated motors and mechanical components of the driver 2220 toachieve the desired response from the flexible catheter assemblyincluding a sheath 220 and catheter or elongate instrument 210 based atleast in part upon a comparison of an actual position the instrumentderived from the localization data to a projected position of theinstrument derived from a kinematic model of the instrument.

As a further example, in one embodiment, the master computer 2241 oranother suitable computer may be configured to determine patientrespiration based on signals 326 received from respective Bragg gratings302 on the one or more Bragg sensor optical fibers 215. Thus, the mastercomputer 2241 can coordinate control of one or more instruments, such asa catheter, monitor one or more instruments, and/or monitor a patient.For example, a controller or computer 340 may be configured to determineone or more position and/or orientation variables of an instrumentdriver 2220, an instrument such as a catheter 210, and a patient's bodybased on detected reflected light signals 326 received from therespective Bragg gratings 302 on the different fibers 215.

In yet another embodiment, in response to the data or analysis of suchdata of detected reflected light signals 326 from the optical fibersensor 215, a controller 340 or master computer 2241 may generate anddisplay a graphical representation of an instrument body such as acatheter 210 by depicting one or more position and/or orientationvariables thereof based upon reflected light signals 326 received fromthe one or more Bragg gratings 302.

Referring to FIG. 22D, an example of a setup joint, instrument mountingbrace or support assembly 2250 (generally referred to as a supportassembly 2250) that supports the instrument driver 2220 above theoperating table 2207 is an arcuate-shaped structure configured toposition the instrument driver 2220 above a patient 1500 lying on thetable 2207 for convenient access to desired locations relative to thepatient 1500. The support assembly 2250 may also be configured to lockthe instrument driver 2220 into position. In this example, the supportassembly 2250 is mounted to the edge of a patient bed 2207 such that anassembly including a catheter 210 mounted on the instrument driver 2220can be positioned for insertion into a patient 1500 and to allow for anynecessary movement of the instrument driver 2220 in order to maneuverthe catheter assembly during a surgical procedure.

As shown in FIGS. 22A, 22D, 22E and 22F, and as illustrated in FIG. 2A,a flexible catheter assembly for use in embodiments includes threecoaxially-associated instruments including an outer sheath catheter 220,an inner coaxially-associated catheter or guide catheter 210, and aworking instrument (not illustrated in FIGS. 22A, 22D, 22E-F) such as aguidewire, pusher wire, ablation catheter, laser ablation fiber,grasper, collapsible basket tool, etc.—a myriad of small working toolsmay be utilized and localized) positioned through the working lumenformed by the inner catheter 210.

In the illustrated example, a splayer 2261 having one or more controlelements or pull wires and a flexible sheath member 220 having a centrallumen. Similarly, a splayer 2262 located proximally of the splayer 2261for the catheter 210 has one or more control elements or pull wires. Thecatheter instrument 210 has a central lumen configured for passage of aworking element or instrument 240. Prior to use, the catheter 210 isinserted into the sheath 220 such that these components are coaxiallypositioned. Both splayers 2261, 2262 are mounted to respective mountingplates on the instrument driver 2220, and the splayers 2261, 2262 arecontrolled to manipulate the catheter and sheath instruments 210, 220.

In one embodiment, a system includes an elongate instrument or catheter210 having one or more control elements or pull wires operativelycoupled to at least one servo motor of the instrument driver 2220 (e.g.as generally illustrated in FIGS. 12 and 13) such that the instrument210 moves in response to actuation of the at least one servo motor. Theoptical fiber sensor 215 supplies localization data indicative of aspatial position of at least a portion of the instrument 210, and thecontroller 340 or other system control element controls actuation of theat least one servo motor in order to control movement of the instrument210 based at least in part upon a comparison of an actual position theinstrument 210 derived from the localization data to a projectedposition of the instrument derived from, for example, a kinematic modelof the instrument 210.

As shown in various system figures, optical fiber sensors 215 can becoupled to or integral with various system components. In certainembodiments, an optical fiber sensor 215 is coupled to or integral witha catheter or elongate instrument 210 (e.g., within a lumen 213 or lumen217), a sheath 220, the instrument driver 2220, the patient's bed 2207,and/or attached to the patient 1500. For example, FIG. 22A illustratesan embodiment in which optical fiber sensors 215 are coupled to twosystem components (instrument driver 2200 and a bed or table 2207) andthe patient 1500, and a catheter or other elongate instrument 210 mayalso include an optical fiber sensor 215. For ease of illustration,various figures show an optical fiber sensor 215 and its associatedsystem component without associated connectors, etc.

FIGS. 23A-C illustrate an elongate catheter 210 in the form of a sheathcatheter 2302 through which another instrument such as a guide catheter2304 may extend. According to embodiments, optical fiber sensors 215 canbe coupled to or integral with the sheath catheter 2302 and/or the guidecatheter 2304, e.g., positioned within a suitable lumen or extendingthrough a wall of an instrument. In the illustrated embodiment, thesheath catheter includes multiple segments 2310(a-n) (generally segment2310). Each segment 2310 may be generally the same shape, e.g. roundring-like structures, but may differ to some degree. Segments 2310 canalso be other shapes, e.g., square, rectangular, triangular, pentagonal,hexagonal, octagonal, circular, spherical, elliptical, star, etc. Pullwires 2320 are operably coupled to each segment 2310 and extend throughaligned passages, apertures or channels 2314 defined by a wall of eachsegment 2310. For example, a pull wire 2320 may be coupled to a distalmost segment 2310 such that placing the pull wire 2320 in tension alsoplaces more proximal segments 2310 in tension. In another embodiment,the pull wires 2320 can be attached to some or all of the segments 2310,e.g., attached to an exterior surface of a segment 2310.

In certain embodiments, the wall of each segment 2310 can also define anaperture 213 (as illustrated in FIG. 2) for an optical fiber sensor 215.In this manner, control elements or pull wires 2320 and optical fibersensors 215 are advantageously routed through the body or wall ofsegments 2320 rather than through an inner or central lumen defined by acollection of segments 2320. In this manner, embodiments advantageouslyreduce the components extending through the inner or central lumen,thereby providing more space through which other instruments anddevices, such as a guide catheter 2304 and/or working instrument 240 maybe inserted. Instruments can also be advanced through the sheathcatheter 2302 more easily since the control elements 2320 and opticalfiber sensor 215 do not interfere with these components. In analternative embodiment, an optical fiber sensor 215 extends through aninner or central lumen defined by the collection of segments 2320.

Individual segments 2320 of a sheath catheter 2302 having shaped,interlocking top and bottom surfaces that allow segment 2320 to matinglyengage adjacent segments 2320. In the illustrated embodiment, eachsegment 2320 includes mating teeth or protrusions 2326 and notches orgrooves 2328 that matingly engagement each other such that interlockingsegments 2320 are not rotatable relative to each other. In this manner,aligned interlocking segments 2320 collectively define a catheter orelongate body structure 120 that defines a lumen that extends throughthe plurality of segment 2320 bodies. While the figures illustrate astructural configuration of one embodiment of a segment 2320, othernumbers and arrangements of teeth or protrusions 2326, notches orgrooves 2328 and apertures 2314, 213 for control elements 2320 andoptical fiber sensors 215 may be utilized. Further, individual segments2320 may have different numbers of teeth or protrusions and notchesdepending on the need to provide additional stability, support, andrigidity to the sheath catheter 2302 when the sheath catheter 2302 isdeployed.

With the sheath 2302 configuration illustrated, segments 2320 and beplaced in tension to place the group of segments 2320 in tension or arigid state, or placed in a relaxed, low tension or flexible state.Thus, one embodiment of a catheter or elongate instrument 120 in theform of a sheath catheter 2302 that may include an optical fiber sensorhas controllable rigidity and can form a platform from which otherinstruments can extend and be controlled and provide rigidity andresistance to twisting or rotational loads on the sheath catheter 2302.

In addition to having an optical fiber sensor 215 as shown in FIG. 23A,a reference sensor may also be coupled to the sheath 2302 proximate thedistal end opening. With this configuration, one or more position and/ororientation variables of the distal end portions of the respectiveinstrument bodies are determined relative to the reference sensor.

With continuing reference to FIG. 23A, and with further reference toFIGS. 24A-D, a rotatable apparatus 2330 is coupled to the sheathcatheter 2302 and provides greater degrees of freedom and movement of aguide catheter 2304, an orientation platform 2340 and/or workinginstrument 240 coupled thereto or associated therewith. A rotatableapparatus 2330 may include an interface or wire guide apparatus 2331 anda rotatable collar, tool base or wire receive apparatus 2332 which arerotatably coupled together. Thus, a tool or other system component maybe rotatably coupled to a distal end portion of a medical instrument,such as a sheath or guide catheter 2302, by manipulation of one or morecontrol elements 207 that extend through grooves formed within rotatableapparatus 2330 to rotate the collar component 2332 clockwise (FIG. 24C)and counter-clockwise (FIG. 24D).

As shown in FIGS. 24A-D, outer surfaces of the interface and collarcomponents 2331, 2332 defines one or more guides, channels or grooves2402 that serve to guide, direct or route control element 2320 (twocontrol elements 2320 a,b are illustrated). In the illustratedembodiment, control elements 2302 wrap around a substantial portion ofthe rotatable collar 2331 such that manipulation of control elements 207results in rotation of the rotatable collar 2332. FIG. 23C furtherillustrates how various control elements 207 may extend through a sheathcatheter 2302 are connected to different components. Thus, pulling orplacing tension on the control element 2320 rotates the collar 2332 andassociated instruments such as a guide catheter 2304 and workinginstrument 240, thereby advantageously providing rotational control aswell as articulation control of system components.

Referring to FIG. 23A, and with further reference to FIGS. 25A-F, anorientation platform 2340 of a robotic instrument system is configuredto control a working instrument 240 (one example of which isillustrated) coupled to a distal end of a catheter instrument 2304 orother instrument of a robotic medical system, e.g., a sheath 220 coveredcatheter 210. In the illustrated example, the interface or platform 2340includes a base member or socket plate 2502 configured for coupling to adistal end of catheter instrument member, a spacer element 2504 andanother socket plate or platform member 2506. The spacer element 2504 isretained or interposed between, and separates, the base member 2502 andthe platform member 2506. The platform member 2506 is movable relativeto the base member 2502 about the spacer element 2504. The interface orplatform 2506 also includes a control element 2320, such as a pull wire,that extends through the catheter member, through an aperture defined bythe base member 2502, and terminating at the platform member 2506. Theplatform 2340 may be used to control an orientation of the platformmember 2506 and an orientation of the working instrument 240 arecontrollably adjustable by manipulation of the control member 2320.

Further aspects of system components illustrated in FIGS. 23A-25F aredescribed in various applications previously incorporated by reference.

FIG. 26A illustrates another manner in which embodiments may beimplemented in which multiple optical fiber sensors 215 are coupled toor integral with multiple catheters coupled to respective rotatableapparatus and orientation apparatus components described above, andwhich are advanced through an outer or master sheath 2600.

In the illustrated embodiment, each sheath catheter 2302 or asub-portion thereof is localized utilizing an optical fiber sensor 215which may be a Fiber Bragg Grating localization sensor. Other systemcomponents, such as an image capture device 1400 (as shown in FIG. 26B)may also be localized with an optical fiber sensor 215. Further, similarto other embodiments discussed above, other system components, such asan instrument driver 2220 and patient bed 1500 may also have opticalfiber sensors 215. With this configuration, embodiments enable theentire environment (image capture device, each flexible arm, the mainproximal arm, etc.) to be well characterized in near-real time, and theimages from the image capture device 1400, such as a fluoroscopy device,may be appropriately associated with representations, cartoons andimages produced from the depicted devices. Thus, embodiments provideapparatus and methods for combining or fusing a shape and localizationmeasuring fiber 215 and robotic surgical system components.

Additionally, similar to apparatus and method embodiments discussedabove, optical fiber sensors 215 coupled to each system component mayprovide for determining and displaying the orientation and the roll ofthe tip of the elongate instruments. This is particularly useful whenplanning surgery or placing leads.

Further, as shown in FIGS. 26A-B, a common reference device, or “controlring” 2602 is provided at the distal end of the master sheath 2600 orsheath like structure that carries the elongate instruments includingsheath catheters 2302 and guide catheters 2304. This control ring 2602can be used as a common reference for all the fibers 215 on elongateinstruments, image capture devices, and the like which may extenddistally from the control ring 2602 location. This common referenceestablishes a common coordinate frame for all the fibers 215 such thatthe shape and location of the fibers 215 may be measured in relation tothe control ring 2602. This arrangement is particularly advantageousbecause the accuracy at the tip will be high due to the short length ofthe fiber 215 run, the twist and roll of the elongate instruments mayresult in smaller errors since the distance between the control ring2602 and the tip is short, and the elongate instruments are all in thesame coordinate frame, which also improves accuracy compared to use ofdifferent coordinate frames.

The location of the control ring 2602 may be localized in the worldcoordinate system by a separate fiber 215 (single or multiple core),which is helpful if elongate instruments, such as catheters 2302, 2304,image capture device 1400 platforms, and the like, which extend distallybeyond the control ring 2602, are coordinated with other externalmedical imaging or data processing systems, such as fluoroscopy systems,magnetic resonance imaging systems, or geometric and/or electronicmappings and datasets.

For embodiments in which multiple elongate instruments 2302 and/or 2304carry single tools, a single elongate instrument carries multiple tools,or multiple elongate instruments each carry multiple tools, fiber basedshape and location measurement devices 215 may be mechanicallyassociated with each tool or each elongate instrument or to both. It isnot necessary that all tools or elongate instruments have a fiber 215attached or coupled thereto. Each fiber 215 could be a single core Bragggrating sensor fiber or a multiple core fiber Bragg grating sensor. Morethan one fiber may be used per tool or per elongate instrument orcatheter.

Accordingly, FIGS. 23A-C and 26A-B are provided to illustrate differentways embodiments can be implemented. It should be understood that aninstrument may include other numbers of sheath catheters 2302, othernumbers of guide catheters 2304, and that each catheter 210 having anoptical fiber sensor 215 coupled thereto may have fibers of variouslengths, positions and configurations.

Additionally, embodiments described above can be utilized with variousmanually or robotically steerable instruments, various localizationsystems and rendering of images to assist an operator, including thosesystems and methods described in the aforementioned patent application,U.S. application Ser. No. 11/637,951, the contents of which werepreviously incorporated herein by reference. FIGS. 27-43 are providedfor reference and illustrate one example of a localization system thatutilizes localization data for closed-loop control of a robotic cathetersystem in which embodiments of the invention may be implemented, andFIGS. 44-49 are provided for reference and illustrate one example ofuser interface presentation of captured or “cartoon” rendered imagesthat are used to assist the operator in controlling a robotic cathetersystem or the like. Additional details regarding these systems areomitted for clarity and described in further detail in application Ser.No. 11/637,951. Embodiments may also utilize other known localizationand user interface presentation systems, and the systems and relatedmethods shown in FIGS. 27-43 are provided as illustrative examples thatmay be used with embodiments.

FIGS. 27-37 depict various aspects of one embodiment of a SimuLink®software control schema for an embodiment of a physical system, withparticular attention to an embodiment of a “master following mode.” Inthis system, an instrument is driven by following instructions from aMID, and a motor servo loop embodiment, which comprises key operationalfunctionality for executing upon commands delivered from the masterfollowing mode to actuate the instrument.

FIG. 27 depicts a high-level view of an embodiment wherein any one ofthree modes may be toggled to operate the primary servo loop 2702. Inidle mode 2704, the default mode when the system is started up, all ofthe motors are commanded via the motor servo block 2706 to servo abouttheir current positions, their positions being monitored with digitalencoders associated with the motors. In other words, idle mode 2704deactivates the motors, while the remaining system stays active. Thus,when the operator leaves idle mode, the system knows the position of therelative components. In auto home mode 2708, cable loops within anassociated instrument driver, such as the instrument driver 2220, arecentered within their cable loop range to ensure substantiallyequivalent range of motion of an associated instrument, such as acatheter, in both directions for a various degree of freedom, such as +and − directions of pitch or yaw, when loaded upon the instrumentdriver. This is a setup mode for preparing an instrument driver beforean instrument is engaged.

In master following mode 2710, the control system receives signals fromthe master input device, and in a closed loop embodiment from both amaster input device and a localization system, and forwards drivesignals to the primary servo loop 2702 to actuate the instrument inaccordance with the forwarded commands Aspects of this embodiment of themaster following mode 2710 are depicted in further detail in FIGS.32-37. Aspects of the primary servo loop and motor servo block 2706 aredepicted in further detail in FIGS. 28-31.

Referring to FIG. 32, a more detailed functional diagram of anembodiment of master following mode 2710 is depicted. As shown in FIG.32, the inputs to functional block 3202 are XYZ position of the masterinput device in the coordinate system of the master input device which,per a setting in the software of the master input device may be alignedto have the same coordinate system as the catheter, and localization XYZposition of the distal tip of the instrument as measured by thelocalization system in the same coordinate system as the master inputdevice and catheter. Referring to FIG. 33, for a more detailed view offunctional block 3202 of FIG. 32, a switch 3302 is provided at block toallow switching between master inputs for desired catheter position, toan input interface 3304 through which an operator may command that theinstrument go to a particular XYZ location in space. Various controlsfeatures may also utilize this interface to provide an operator with,for example, a menu of destinations to which the system shouldautomatically drive an instrument, etc. Also depicted in FIG. 33 is amaster scaling functional block 3306 which is utilized to scale theinputs coming from the master input device with a ratio selectable bythe operator. The command switch 3302 functionality includes a low passfilter to weight commands switching between the master input device andthe input interface 3304, to ensure a smooth transition between thesemodes.

Referring back to FIG. 32, desired position data in XYZ terms is passedto the inverse kinematics block 3206 for conversion to pitch, yaw, andextension (or “insertion”) terms in accordance with the predictedmechanics of materials relationships inherent in the mechanical designof the instrument.

The kinematic relationships for many catheter instrument embodiments maybe modeled by applying conventional mechanics relationships. In summary,a control-element-steered catheter instrument is controlled through aset of actuated inputs. In a four-control-element catheter instrument,for example, there are two degrees of motion actuation, pitch and yaw,which both have + and − directions. Other motorized tensionrelationships may drive other instruments, active tensioning, orinsertion or roll of the catheter instrument. The relationship t,between actuated inputs and the catheter's end point position as afunction of the actuated inputs is referred to as the “kinematics” ofthe catheter.

Referring to FIG. 38, the “forward kinematics” expresses the catheter'send-point position as a function of the actuated inputs while the“inverse kinematics” expresses the actuated inputs as a function of thedesired end-point position. Accurate mathematical models of the forwardand inverse kinematics are essential for the control of a roboticallycontrolled catheter system. For clarity, the kinematics equations arefurther refined to separate out common elements, as shown in FIG. 38.The basic kinematics describes the relationship between the taskcoordinates and the joint coordinates. In such case, the taskcoordinates refer to the position of the catheter end-point while thejoint coordinates refer to the bending (pitch and yaw, for example) andlength of the active catheter. The actuator kinematics describes therelationship between the actuation coordinates and the jointcoordinates. The task, joint, and bending actuation coordinates for therobotic catheter are illustrated in FIG. 39. By describing thekinematics in this way we can separate out the kinematics associatedwith the catheter structure, namely the basic kinematics, from thoseassociated with the actuation methodology.

The development of the catheter's kinematics model is derived using afew essential assumptions. Included are assumptions that the catheterstructure is approximated as a simple beam in bending from a mechanicsperspective, and that control elements, such as thin tension wires,remain at a fixed distance from the neutral axis and thus impart auniform moment along the length of the catheter.

In addition to the above assumptions, the geometry and variables shownin FIG. 40 are used in the derivation of the forward and inversekinematics. The basic forward kinematics relates catheter taskcoordinates to joint coordinates, as expressed in further detail in U.S.application Ser. No. 11/637,951. The actuator forward kinematics,relating the joint coordinates to the actuator coordinates are alsoexpressed in application Ser. No. 11/637,951

As illustrated in FIG. 38, the catheter's end-point position can bepredicted given the joint or actuation coordinates by using the forwardkinematics equations described above. Calculation of the catheter'sactuated inputs as a function of end-point position, referred to as theinverse kinematics, can be performed numerically, using a nonlinearequation solver such as Newton-Raphson. A more desirable approach, andthe one used in this illustrative embodiment, is to develop aclosed-form solution which can be used to calculate the requiredactuated inputs directly from the desired end-point positions.

As with the forward kinematics, we separate the inverse kinematics intothe basic inverse kinematics, which relates joint coordinates to thetask coordinates, and the actuation inverse kinematics, which relatesthe actuation coordinates to the joint coordinates. The basic inversekinematics, relating the joint coordinates to the catheter taskcoordinates is expressed in application Ser. No. 11/637,951. Theactuator inverse kinematics, relating the actuator coordinates to thejoint coordinates is also expressed in application Ser. No. 11/637,951.

Referring back to FIG. 32, pitch, yaw, and extension commands are passedfrom the inverse kinematics block 3206 to a position control block 3204along with measured localization data. FIG. 37 provides a more detailedview of the position control block 3204. After measured XYZ positiondata comes in from the localization system, it goes through an inversekinematics block 3702 to calculate the pitch, yaw, and extension theinstrument needs to have in order to travel to where it needs to be.Comparing 3704 these values with filtered desired pitch, yaw, andextension data from the master input device, integral compensation isthen conducted with limits on pitch and yaw to integrate away the error.In this embodiment, the extension variable does not have the same limits3706, as do pitch and yaw 3708. As will be apparent to those skilled inthe art, having an integrator in a negative feedback loop forces theerror to zero. Desired pitch, yaw, and extension commands are nextpassed through a catheter workspace limitation block 3208, which may bea function of the experimentally determined physical limits of theinstrument beyond which componentry may fail, deform undesirably, orperform unpredictably or undesirably. This workspace limitationessentially defines a volume similar to a cardioid-shaped volume aboutthe distal end of the instrument. Desired pitch, yaw, and extensioncommands, limited by the workspace limitation block, are then passed toa catheter roll correction block 3210.

This functional block is depicted in further detail in FIG. 34, andessentially comprises a rotation matrix for transforming the pitch, yaw,and extension commands about the longitudinal, or “roll”, axis of theinstrument—to calibrate the control system for rotational deflection atthe distal tip of the catheter that may change the control elementsteering dynamics. For example, if a catheter has no rotationaldeflection, pulling on a control element located directly up at twelveo'clock should urge the distal tip of the instrument upward. If,however, the distal tip of the catheter has been rotationally deflectedby, say, ninety degrees clockwise, to get an upward response from thecatheter, it may be necessary to tension the control element that wasoriginally positioned at a nine o'clock position. The catheter rollcorrection schema depicted in FIG. 34 provides a means for using arotation matrix to make such a transformation, subject to a rollcorrection angle, such as the ninety degrees in the above example, whichis input, passed through a low pass filter, turned to radians, and putthrough rotation matrix calculations.

In one embodiment, the roll correction angle is determined throughexperimental experience with a particular instrument and path ofnavigation. In another embodiment, the roll correction angle may bedetermined experimentally in-situ using the accurate orientation dataavailable from the preferred localization systems. In other words, withsuch an embodiment, a command to, for example, bend straight up can beexecuted, and a localization system can be utilized to determine atwhich angle the defection actually went—to simply determine the in-situroll correction angle.

Referring briefly back to FIG. 32, roll corrected pitch and yawcommands, as well as unaffected extension commands, are output from thecatheter roll correction block 3210 and may optionally be passed to aconventional velocity limitation block 3212. Referring to FIG. 35, pitchand yaw commands are converted from radians to degrees, andautomatically controlled roll may enter the controls picture to completethe current desired position 3502 from the last servo cycle. Velocity iscalculated by comparing the desired position from the previous servocycle, as calculated with a conventional memory block calculation 3506,with that of the incoming commanded cycle. A conventional saturationblock 3504 keeps the calculated velocity within specified values, andthe velocity-limited command 3506 is converted back to radians andpassed to a tension control block 3514.

Tension within control elements may be managed depending upon theparticular instrument embodiment, as described above in reference to thevarious instrument embodiments and tension control mechanisms. As anexample, FIG. 36 depicts a pre-tensioning block 3602 with which a givencontrol element tension is ramped to a present value. An adjustment isthen added to the original pre-tensioning based upon a preferablyexperimentally-tuned matrix pertinent to variables, such as the failurelimits of the instrument construct and the incoming velocity-limitedpitch, yaw, extension, and roll commands This adjusted value is thenadded 3604 to the original signal for output, via gear ratio adjustment,to calculate desired motor rotation commands for the various motorsinvolved with the instrument movement. In this embodiment, extension,roll, and sheath instrument actuation 3606 have no pre-tensioningalgorithms associated with their control. The output is then completefrom the master following mode functionality, and this output is passedto the primary servo loop 2702.

Referring back to FIG. 27, incoming desired motor rotation commands fromeither the master following mode 2710, auto home mode 2708, or idle mode2704 in the depicted embodiment are fed into a motor servo block 2706,which is depicted in greater detail in FIGS. 28-31.

Referring to FIG. 28, incoming measured motor rotation data from digitalencoders and incoming desired motor rotation commands are filtered usingconventional quantization noise filtration at frequencies selected foreach of the incoming data streams to reduce noise while not adding unduedelays which may affect the stability of the control system. As shown inFIGS. 30-31, conventional quantization filtration is utilized on themeasured motor rotation signals at about 200 hertz in this embodiment,and on the desired motor rotation command at about 15 hertz. Thedifference 2804 between the quantization filtered values forms theposition error which may be passed through a lead filter, the functionalequivalent of a proportional derivative (“PD”)+low pass filter. Inanother embodiment, conventional PID, lead/lag, or state spacerepresentation filter may be utilized. The lead filter of the depictedembodiment is shown in further detail in FIG. 29.

In particular, the lead filter embodiment in FIG. 29 comprises a varietyof constants selected to tune the system to achieve desired performance.The depicted filter addresses the needs of one embodiment of a 4-controlelement guide catheter instrument with independent control of each offour control element interface assemblies for +/−pitch and +/−yaw, andseparate roll and extension control. As demonstrated in the depictedembodiment, insertion and roll have different inertia and dynamics asopposed to pitch and yaw controls, and the constants selected to tunethem is different. The filter constants may be theoretically calculatedusing conventional techniques and tuned by experimental techniques, orwholly determined by experimental techniques, such as setting theconstants to give a sixty degree or more phase margin for stability andspeed of response, a conventional phase margin value for medical controlsystems.

In an embodiment where a tuned master following mode is paired with atuned primary servo loop, an instrument and instrument driver, such asthose described above, may be “driven” accurately in three-dimensionswith a remotely located master input device. Other preferred embodimentsincorporate related functionalities, such as haptic feedback to theoperator, active tensioning with a split carriage instrument driver,navigation utilizing direct visualization and/or tissue models acquiredin-situ and tissue contact sensing, and enhanced navigation logic.

Referring to FIG. 39, in one embodiment, the master input device may bea haptic master input device, such as those available from SensAbleTechnologies, Inc., under the trade name Phantoms® Haptic Devices, andthe hardware and software required for operating such a device may atleast partially reside on the master computer. The master XYZ positionsmeasured from the master joint rotations and forward kinematics aregenerally passed to the master computer via a parallel port or similarlink and may subsequently be passed to a control and instrument drivercomputer. With such an embodiment, an internal servo loop for aPhantoms® Haptic Device generally runs at a much higher frequency in therange of 1,000 Hz, or greater, to accurately create forces and torquesat the joints of the master.

Referring to FIG. 42, a sample flowchart of a series of operationsleading from a position vector applied at the master input device to ahaptic signal applied back at the operator is depicted. A vector 4202associated with a master input device move by an operator may betransformed into an instrument coordinate system, and in particular to acatheter instrument tip coordinate system, using a simple matrixtransformation 4204. The transformed vector 4206 may then be scaled 4208per the preferences of the operator, to produce a scaled-transformedvector 4210. The scaled-transformed vector may be sent to both thecontrol and instrument driver computer 4212 preferably via a serialwired connection, and to the master computer for a catheter workspacecheck 4214 and any associated vector modification 4216. This is followedby a feedback constant multiplication 4218 chosen to produce preferredlevels of feedback, such as force, in order to produce a desired forcevector 4220, and an inverse transform 4222 back to a force vector 4224in the master input device coordinate system for associated hapticsignaling to the operator in that coordinate system.

A conventional Jacobian may be utilized to convert a desired forcevector 4220 to torques desirably applied at the various motorscomprising the master input device, to give the operator a desiredsignal pattern at the master input device. Given this embodiment of asuitable signal and execution pathway, feedback to the operator in theform of haptics, or touch sensations, may be utilized in various ways toprovide added safety and instinctiveness to the navigation features ofthe system, as discussed in further detail below.

FIG. 43 is a system block diagram including haptics capability. As shownin summary form in FIG. 43, encoder positions on the master inputdevice, changing in response to motion at the master input device, aremeasured 4302, sent through forward kinematics calculations 4304pertinent to the master input device to get XYZ spatial positions of thedevice in the master input device coordinate system 4306, thentransformed 4308 to switch into the catheter coordinate system and(perhaps) transform for visualization orientation and preferred controlsorientation, to facilitate “instinctive driving”.

The transformed desired instrument position 4310 may then be sent downone or more controls pathways to, for example, provide haptic feedback4312 regarding workspace boundaries or navigation issues, and provide acatheter instrument position control loop 4314 with requisite catheterdesired position values, as transformed utilizing catheter inverse 4316kinematics relationships for the particular instrument into yaw, pitch,and extension, or insertion, terms 4318 pertinent to operating theparticular catheter instrument with open or closed loop control.

As further reference, referring to FIG. 44, a systemic view configuredto produce an overlaid image is depicted. A known fluoroscopy system4402 outputs an electronic image in formats such as those known as“S-video” or “analog high-resolution video”. In image output interface4404 of a fluoroscopy system 4402 may be connected to an input interfaceof a computer 4410 based image acquisition device, such as those knownas “frame grabber” 4412 image acquisition cards, to facilitate intake ofthe video signal from the fluoroscopy system 4402 into the frame grabber4412, which may be configured to produce bitmap (“BMP”) digital imagedata, generally comprising a series of Cartesian pixel coordinates andassociated grayscale or color values which together may be depicted asan image. The bitmap data may then be processed utilizing computergraphics rendering algorithms, such as those available in conventionalOpenGL graphics libraries 4414. In summary, conventional OpenGLfunctionality enables a programmer or operator to define objectpositions, textures, sizes, lights, and cameras to producethree-dimensional renderings on a two-dimensional display. The processof building a scene, describing objects, lights, and camera position,and using OpenGL functionality to turn such a configuration into atwo-dimensional image for display is known in computer graphics asrendering. The description of objects may be handled by forming a meshof triangles, which conventional graphics cards are configured tointerpret and output displayable two-dimensional images for aconventional display or computer monitor, as would be apparent to oneskilled in the art. Thus the OpenGL software 4414 may be configured tosend rendering data to the graphics card 4416, which may then be outputto a conventional display 4420.

A triangular mesh generated with OpenGL software may be used to form acartoon-like rendering of an elongate instrument moving in spaceaccording to movements from, for example, a master following modeoperational state, may be directed to a computer graphics card, alongwith frame grabber and OpenGL processed fluoroscopic video data. Thus amoving cartoon-like image of an elongate instrument would bedisplayable. To project updated fluoroscopic image data onto aflat-appearing surface in the same display, a plane object,conventionally rendered by defining two triangles, may be created, andthe updated fluoroscopic image data may be texture mapped onto theplane. Thus the cartoon-like image of the elongate instrument may beoverlaid with the plane object upon which the updated fluoroscopic imagedata is texture mapped. Camera and light source positioning may bepre-selected, or selectable by the operator through the mouse or otherinput device, for example, to enable the operator to select desiredimage perspectives for his two-dimensional computer display. Theperspectives, which may be defined as origin position and vectorposition of the camera, may be selected to match with standard viewscoming from a fluoroscopy system, such as anterior/posterior and lateralviews of a patient lying on an operating table. When the elongateinstrument is visible in the fluoroscopy images, the fluoroscopy planeobject and cartoon instrument object may be registered with each otherby ensuring that the instrument depicted in the fluoroscopy plane linesup with the cartoon version of the instrument. In one embodiment,several perspectives are viewed while the cartoon object is moved usingan input device such as a mouse, until the cartoon instrument object isregistered with the fluoroscopic plane image of the instrument. Becauseboth the position of the cartoon object and fluoroscopic image objectmay be updated in real time, an operator, or the system automaticallythrough image processing of the overlaid image, may interpretsignificant depicted mismatch between the position of the instrumentcartoon and the instrument fluoroscopic image as contact with astructure that is inhibiting the normal predicted motion of theinstrument, error or malfunction in the instrument, or error ormalfunction in the predictive controls software underlying the depictedposition of the instrument cartoon.

Referring back to FIG. 44, other video signals (not shown) may bedirected to the image grabber 4412, besides that of a fluoroscopy system4402, simultaneously. For example, images from an intracardiac echoultrasound (“ICE”) system, intravascular ultrasound (“IVUS”), or othersystem may be overlaid onto the same displayed image simultaneously.Further, additional objects besides a plane for texture mappingfluoroscopy or an elongate instrument cartoon object may be processedusing OpenGL or other rendering software to add additional objects tothe final display.

Referring to FIGS. 45A-B and 46, an elongate instrument is a roboticguide catheter, and fluoroscopy and ICE are utilized to visualize thecardiac and other surrounding tissues, and instrument objects. Referringto FIG. 45A, a fluoroscopy image has been texture mapped upon a planeconfigured to occupy nearly the entire display area in the background.Visible in the fluoroscopy image as a dark elongate shadow is the actualposition, from fluoroscopy, of the guide catheter instrument relative tothe surrounding tissues. Overlaid in front of the fluoroscopy plane is acartoon rendering (white in color in FIGS. 45A-B) of the predicted, or“commanded”, guide catheter instrument position. Further overlaid infront of the fluoroscopy plane is a small cartoon object representingthe position of the ICE transducer, as well as another plane objectadjacent the ICE transducer cartoon object onto which the ICE image datais texture mapped by a technique similar to that with which thefluoroscopic images are texture mapped upon the background plane object.Further, mouse objects, software menu objects, and many other objectsmay be overlaid. FIG. 45A shows a similar view with the instrument in adifferent position. For illustrative purposes, FIGS. 45A-B depictmisalignment of the instrument position from the fluoroscopy object, ascompared with the instrument position from the cartoon object. Asdescribed above, the various objects may be registered to each other bymanually aligning cartoon objects with captured image objects inmultiple views until the various objects are aligned as desired. Imageprocessing of markers and shapes of various objects may be utilized toautomate portions of such a registration process.

Referring to FIG. 46, a schematic is depicted to illustrate how variousobjects, originating from actual medical images processed by framegrabber, originating from commanded instrument position control outputs,or originating from computer operating system visual objects, such asmouse, menu, or control panel objects, may be overlaid into the samedisplay.

Further, a pre-acquired image of pertinent tissue, such as athree-dimensional image of a heart, may be overlaid and registered toupdated images from real-time medical imaging modalities as well. Forexample, in one embodiment, a beating heart may be preoperatively imagedusing gated computed tomography (CT). The result of CT imaging may be astack of CT data slices. Utilizing either manual or automatedthresholding techniques, along with interpolation, smoothing, and/orother conventional image processing techniques available in softwarepackages such as that sold under the tradename Amira® product availablefrom Mercury Computer Systems of Chelmsford, Mass., a triangular meshmay be constructed to represent a three-dimensional cartoon-like objectof the heart, saved, for example, as an object (“.obj”) file, and addedto the rendering as a heart object. The heart object may then beregistered as discussed above to other depicted images, such asfluoroscopy images, utilizing known tissue landmarks in multiple views,and contrast agent techniques to particularly see show certain tissuelandmarks, such as the outline of an aorta, ventricle, or left atrium.The cartoon heart object may be moved around, by mouse, for example,until it is appropriately registered in various views, such asanterior/posterior and lateral, with the other overlaid objects.

Referring to FIG. 47, a distributed system architecture embodiment isdepicted. A master control computer running a real-time operatingsystem, such as QNX, is connected to each of the other computers in thesystem by a 1 gigabit Ethernet “Real-time Network”, and also by a 100megabit Ethernet “System Network”, using a conventional high-speedswitch. This enables localized custom computing for various devices tobe pushed locally near the device, without the need for large cabling ora central computing machine. In one embodiment, the master controlcomputer may be powered by an Intel® Xeon® processor available fromIntel Corporation of Santa Clara, Calif., the visualization computerpowered by a personal computer (PC) with a high-end microprocessor basedon the Intel architecture running Windows XP and having multiple videocards and frame grabbers, the instrument driver and master input deviceCPUs being PC or “EPIC” standard boards with two Ethernet connectionsfor the two networks. An additional master input device, touchscreen,and console may be configured into an addition operator workstation in adifferent location relative to the patient. The system is veryexpandable—new devices may be plugged into the switch and placed ontoeither of the two networks.

Referring to FIG. 47, two high resolution frame grabber boards 4702acquire images from two fluoro devices (or one in the case of singleplane fluoro), which a nominal resolution frame grabber board 4702acquires images from an intracardiac echo system. Such image data may beutilized for overlaying, etc., as described in reference to FIGS. 44-46,and displayed on a display, such as the #2 display, using a video card4704 of the visualization computer, as depicted. Heart monitor data,from a system such as the Prucka CardioLab EP System distributed by GEHealthcare of Waukesha, Wis., may be directly channeled from video outports on the heart monitor device to one of the displays. Such data mayalso be acquired by a frame grabber. Similarly, electrophysiologicalmapping and treatment data and images from systems available fromdistributors such as Endocardial Solutions, Biosense Webster, Inc.,etc., may be directed as video to a monitor, or data to a dataacquisition board, data bus, or frame grabber. Preferably the mastercontrol computer has some interface connectivity with theelectrophysiology system as well to enable single master input devicedriving of such device, etc.

Referring to FIG. 48, a depiction of the software and hardwareinteraction is depicted. Essentially, the master state machinefunctionality of the master control system real-time operating systemallows for very low latency control of processes used to operate masterinput device algorithms and instrument driver algorithms, such as thosedescribed in reference to the control systems description above. Indeed,XPC may be utilized to develop algorithm code, but preferably auniversal modeling language such as IBM Rational Rose from IBMCorporation of Armonk, N.Y., or Rhapsody of I-Logix of Andover, Mass.,is utilized to build code and documentation using a graphical interface.With the gigabit real-time network, in a matter of 200-300 microseconds,the master input device or instrument driver algorithms are able tocommunicate with FPGA driver code in the electronics and hardware nearthe pertinent device to exchange new values, etc., and confirm that allis well from a safety perspective. This leaves approximately 700microseconds for processing if a 1 millisecond motor shutoff time isrequired if all is not well—and this is easily achievable with thedescribed architecture. The visualization PC may be configured to cycledata from the master control computer at a lower frequency, about 20milliseconds. FIG. 49 illustrates the software interaction of oneembodiment.

Although particular embodiments have been shown and described, it shouldbe understood that the above discussion is not intended to limit thescope of these embodiments. While embodiments and variations of the manyaspects of the invention have been disclosed and described herein, suchdisclosure is provided for purposes of explanation and illustrationonly. Many combinations and permutations of the disclosed embodimentsare useful in minimally invasive surgery, and the system is configuredto be flexible for use with other system components and in otherapplications. Thus, various changes and modifications may be madewithout departing from the scope of the claims.

For example, although embodiment are described with reference to atelemanipulation system or robotic control system, embodiments may alsobe manually controlled by a surgeon, e.g., near the proximal section ofthe sheath catheter. Embodiments are advantageously suited for minimallyinvasive procedures, they may also be utilized in other, more invasiveprocedures that utilize extension tools and may be used in surgicalprocedures other than treatment of arrhythmias such as atrialfibrillation.

Further, although embodiments are described with reference to a fiber orfiber sensor coupled to or integral with a catheter, embodiments mayalso involve a fiber or fiber sensor coupled to or integral with asheath, multiple catheters or other elongate instruments, e.g., thatextend through a sheath, a working instrument, and other systemcomponents such as an a localization sensor, an instrument driver, apatient's bed, a patient, and combinations thereof. Further, such fibersmay be positioned within an elongate instrument or coupled to orintegral with an outer surface thereof.

Moreover, depending on the configuration of a system and systemcomponents, a “controller” may be or include a unit coupled to a fiber,may be, or include, a computer or processor of a robotic instrumentsystem (e.g., in an electronics rack or at a user workstation), or acombination thereof. Further, a unit that sends and/or receives lightmay be a separate component or integrated within a controller componentof a robotic instrument system. Thus, a “controller” may be a standaloneor integrated component or include multiple components that are operablycoupled together.

Further, it should be understood that embodiments of an optical fibersensor and apparatus, system and methods including or involving the samemay be used in various applications and be configured in variousdifferent ways. For example, they may be coupled to or integral withvarious system components intended for insertion into a patent and thatare intended for external use. Optical fiber sensors may also includevarious numbers of FBGs, which may be of the same or differentwavelengths, and may be arranged in different ways. Further, variousoptical systems can be used with embodiments, and the exemplarycomponents and read out system are provided as one example of howembodiments may be implemented.

Because one or more components of embodiments may be used in minimallyinvasive surgical procedures, the distal portions of these instrumentsmay not be easily visible to the naked eye. As such, embodiments of theinvention may be utilized with various imaging modalities such asmagnetic resonance (MR), ultrasound, computer tomography (CT), X-ray,fluoroscopy, etc. may be used to visualize the surgical procedure andprogress of these instruments. It may also be desirable to know theprecise location of any given catheter instrument and/or tool device atany given moment to avoid undesirable contacts or movements. Thus,embodiments may be utilized with localization techniques that arepresently available may be applied to any of the apparatuses and methodsdisclosed above. Further, a plurality of sensors, including those forsensing patient vitals, temperature, pressure, fluid flow, force, etc.,may be combined with the various embodiments of flexible catheters anddistal orientation platforms.

Various system components including catheter components may be made withmaterials and techniques similar to those described in detail in U.S.patent application Ser. No. 11/176,598, incorporated by reference hereinin its entirety. Further, various materials may be used to fabricate andmanufacture sheath catheter segment, rotatable apparatus and orientationplatform devices. For example, it is contemplated that in addition tothat disclosed above, materials including, but not limited to, stainlesssteel, copper, aluminum, nickel-titanium alloy (Nitinol), Flexinol®(available from Toki of Japan), titanium, platinum, iridium, tungsten,nickel-chromium, silver, gold, and combinations thereof, may be used tomanufacture components such as control elements, control cables,segments, gears, plates, ball units, wires, springs, electrodes,thermocouples, etc. Similarly, non-metallic materials including, but notlimited to, polypropylene, polyurethane (Pebax®), nylon, polyethylene,polycarbonate, Delrin®, polyester, Kevlar®, carbon, ceramic, silicone,Kapton® polyimide, Teflon® coating, polytetrafluoroethylene (PTFE),plastic (non-porous or porous), latex, polymer, etc. may be used to makethe various parts of a catheter, orientation platform, tool, etc.

Additionally, certain system components are described as having lumensthat are configured for carrying or passage of control elements, controlcables, wires, and other catheter instruments. Such lumens may also beused to deliver fluids such as saline, water, carbon dioxide, nitrogen,helium, for example, in a gaseous or liquid state, to the distal tip.Further, some embodiments may be implemented with an open loop or closedloop cooling system wherein a fluid is passed through one or more lumensin the sidewall of the catheter instrument to cool the catheter or atool at the distal tip.

Further, embodiments may be utilized with various working instrumentsincluding end effectors including, for example, a Kittner dissector, amulti-fire coil tacker, a clip applier, a cautery probe, a shovelcautery instrument, serrated graspers, tethered graspers, helicalretraction probe, scalpel, basket capture device, irrigation tool,needle holders, fixation device, transducer, and various other graspers.A number of other catheter type instruments may also be utilizedtogether with certain embodiments including, but not limited to, amapping catheter, an ablation catheter, an ultrasound catheter, a laserfiber, an illumination fiber, a wire, transmission line, antenna, adilator, an electrode, a microwave catheter, a cryo-ablation catheter, aballoon catheter, a stent delivery catheter, a fluid/drug delivery tube,a suction tube, an optical fiber, an image capture device, an endoscope,a Foley catheter, Swan-Ganz catheter, fiberscope, etc. Thus, it iscontemplated that one or more catheter instruments may be insertedthrough one or more lumens of a flexible catheter instrument, flexiblesheath instrument, or any catheter instrument to reach a surgical siteat the distal tip. Similarly, it is contemplated that one or morecatheter instruments may be passed through an orientation platform to aregion of interest.

While multiple embodiments and variations of the many aspects of thepresent disclosure have been disclosed and described herein, suchdisclosure is provided for purposes of illustration only. Manycombinations and permutations of the disclosed system are useful inminimally invasive medical intervention and diagnosis, and the system isconfigured to be flexible. The foregoing illustrated and describedembodiments of the present disclosure are susceptible to variousmodifications and alternative forms, and it should be understood thatthe present disclosure generally, as well as the specific embodimentsdescribed herein, are not limited to the particular forms or methodsdisclosed, but also cover all modifications, equivalents andalternatives. Further, the various features and aspects of theillustrated embodiments may be incorporated into other embodiments, evenif no so described herein, as will be apparent to those skilled in theart.

What is claimed is:
 1. An instrument system, comprising: an elongateinstrument body; and an optical fiber sensor comprising an elongateoptical fiber coupled to the elongate instrument body, wherein a portionof the optical fiber is coupled to the elongate instrument body in amanner to provide slack in the fiber to allow for axial extension of theelongate instrument body relative to the optical fiber.
 2. Theinstrument system of claim 1, wherein the optical fiber comprises one ormore Bragg gratings.
 3. The instrument system of claim 1, wherein theoptical fiber includes a service loop provided at a proximal end thereofso as to provide the slack in the optical fiber.
 4. The instrumentsystem of claim 3, wherein the slack in the optical fiber is configuredto prevent breaking or excessive straining of the optical fiber.
 5. Theinstrument system of claim 3, wherein the optical fiber is constrainedat a distal end thereof.
 6. An instrument system, comprising: anelongate instrument body comprising a substantially rigid proximalportion and a flexible distal portion; and an optical fiber sensorcomprising an optical fiber coupled to the elongate instrument body,wherein a portion of the optical fiber is coupled at a known referencelocation on the proximal portion of the elongate instrument body.
 7. Theinstrument system of claim 6, wherein the optical fiber comprises one ormore Bragg gratings.
 8. An instrument system, comprising: an elongateinstrument body; and an optical fiber coupled to the elongate instrumentbody, wherein at least one of the optical fiber and the elongateinstrument body has a structural attribute that prevents twisting of theoptical fiber relative to the elongate instrument body.
 9. The system ofclaim 8, wherein the structural attribute comprises an oval structure ora flat or beveled edge.
 10. The system of claim 8, wherein thestructural attributes include a groove and a structure that matinglyengages with the groove.
 11. The system of claim 8, wherein the elongateinstrument body is a catheter.
 12. The system of claim 8, wherein theoptical fiber comprises one or more Bragg gratings.